Working on Function

WORKING ON FUNCTIONS

A. Multiple Choice Questions.

Q1. If return statement is not used inside the function, the function will return:

(a) 0 (b) None object

Q2. Which of the following keywords marks the beginning of the function block?

(a) func (b) define

Q3. What is the area of memory called, which stores the parameters and local variables of a function call?

(a) a heap (b) storage area

def func2():

print(2 + 3)

def main()

print ("hello")

Q4. Find the errors in following function definitions:

(a) (b)

square (a)

return a * a

def compute():

print (x * x)

Answer

(a) Colon is missing at the end of function header.

(b) There is no error.

(d) def keyword at the beginning and colon at the end of function header are missing.

B. Multiple Choice Questions

Q1. What is the default return value for a function that does not return any value explicitly ?

a. None b. int

c. double d. null

Q2. Which of the following items are present in the function header?

a. function name only b. both function name and parameter list

c. parameter list only d. return value

Q3. Which of the following keywords marks the beginning of the function block?

a. func b. define

c. def d. function

Q4. What is the name given to that area of memory, where the system stores the parameters and local variables of a function call?

a. a heap b. storage area

c. a stack d. an array

Q5. Pick one the following statements to correctly complete the function body in the given code snippet.

def f(number):

#Missing function body

print(f(5))

a. return "number" b. print(number)

c. print("number") d. return number

Q6. Which of the following function headers is correct?

a. def f(a = 1, b): b. def f(a = 1, b, c = 2):

c. def f(a = 1, b = 1, c = 2): d. def f(a = 1, b = 1, c = 2, d):

Q7. Which of the following statements is not true for parameter passing to functions?

a. You can pass positional arguments in any order.

b. You can pass keyword arguments in any order.

c. You can call a function with positional and keyword arguments.

d. Positional arguments must be before keyword arguments in a function call.

Q8. Which of the following is not correct in context of Positional and Default parameters in Python functions?

a. Default parameters must occur to the right of Positional parameters.

b. Positional parameters must occur to the right of Default parameters.

c. Positional parameters must occur to the left of Default parameters.

d. All parameters to the right of a Default parameter must also have Default values.

Q9. Which of the following is not correct in context of scope of variables?

a. Global keyword is used to change value of a global variable in a local scope.

b. Local keyword is used to change value of a local variable in a global scope.

c. Global variables can be accessed without using the global keyword in a local scope.

d. Local variables cannot be used outside its scope.

Q10. Which of the following function calls can be used to invoke the below function definition?

def test(a, b, c, d)

a. test(1, 2, 3, 4) b. test(a = 1, 2, 3, 4)

c. test(a = 1, b = 2, c = 3, 4) d. test(a = 1, b = 2, c = 3, d = 4)

Q11. Which of the following function calls will cause Error while invoking the below function definition?

def test(a, b, c, d)

a. test(1, 2, 3, 4) b. test(a = 1, 2, 3, 4)

c. test(a = 1, b = 2, c = 3, 4) d. test(a = 1, b = 2, c = 3, d = 4)

Q12. For a function header as follows: def Calc(X,Y = 20):

Which of the following function calls will give an error?

a. Calc(15, 25) b. Calc(X = 15, Y = 25)

c. Calc(Y = 25) d.Calc(X = 25)

Q13. What is a variable defined outside all the functions referred to as?

a. A static variable b. A global variable

c. A local variable d. An automatic variable

Q14. What is a variable defined inside a function referred to as?

a. A static variable b. A global variable

c. A local variable d. An automatic variable

Q15. Carefully observe the code and give the answer.

def function1(a):

a = a + '1'

a = a * 2

>>>function1("hello")

a. indentation Error b. cannot perform mathematical operation on strings

c. hello2 d. hello2hello2

Q16. What is the result of this code?

def print_double(x):

print(2 ** x)

print_double(3)

a. 8 b. 6

b. 4 d. 10

Q17. What is the order of resolving scope of a name in a Python program ?

a. B G E L b. L E G B

c. G E B L d. L B E G

Q18. Which of the given argument types can be skipped from a function call?

a. positional arguments b. keyword arguments

c. named arguments d. default arguments

C. Fill in the Blanks

Q1. A function is a subprogram that acts on data and often returns a value.

Q2. Python names the top level segment (main program) as __main__.

Q3. In Python, program execution begins with first statement of __main__ segment.

Q4. The values being passed through a function-call statement are called arguments / actual parameters / actual arguments.

Q5. The values received in the function definition/header are called parameters / formal parameters / formal arguments.

Q6. A parameter having default value in the function header is known as a default parameter.

Q7. A default argument can be skipped in the function call statement.

Q8. Keyword arguments are the named arguments with assigned values being passed in the function call statement.

Q9. A void function also returns a None value to its caller.

Q10. By default, Python names the segment with top-level statements (main program) as __main__.

Q11. The flow of execution refers to the order in which statements are executed during a program run.

Q12. The default value for a parameter is defined in function header.

D. State True or False.

Q1. Non-default arguments can be placed before or after a default argument in a function definition. F

Q2. A parameter having default value in the function header is known as a default parameter. T

Q3. The first line of function definition that begins with keyword def and ends with a colon (:), is also known as function header. T

Q4.Variables that are listed within the parentheses of a function header are called function variables.

Q5. In Python, the program execution begins with first statement of __main__ segment. T

Q6. Default parameters cannot be skipped in function call. F

Q7. The default values for parameters are considered only if no value is provided for that parameter in the function call statement. T

Q8. A Python function may return multiple values. T

Q9. A void function also returns a value i.e., None to its caller. T

Q10. Variables defined inside functions can have global scope. F

Q11. A local variable having the same name as that of a global variable, hides the global variable in its function. T

E. Assertions and Reasons

Q1. Assertion. A function is a subprogram.

Reason. A function exists within a program and works within it when called.

Answer: (a) Both Assertion and Reason are true and Reason is the correct explanation of Assertion.

Explanation: A function is a subprogram that acts on data and often returns a value. It is a self-contained unit of code that performs a specific task within a larger program. Functions are defined within a program and can be called upon to execute a specific set of instructions when needed.

Q2. Assertion. Non-default arguments cannot follow default arguments in a function call.

Reason. A function call can have different types of arguments.

Answer (b) Both Assertion and Reason are true but Reason is not the correct explanation of Assertion.

Explanation: In a function call, any parameter cannot have a default value unless all parameters appearing on its right have their default values. Hence, non-default arguments cannot follow default arguments in a function call. Python supports three types of formal arguments:

(a) Positional arguments (b) Default arguments (c) keyword arguments

Q3. Assertion. A parameter having a default in function header becomes optional in function call.

Reason. A function call may or may not have values for default arguments.

Answer: (a) Both Assertion and Reason are true and Reason is the correct explanation of Assertion.

Explanation: When a parameter in a function header has a default value, it means that if no value is provided for that parameter during the function call, the default value will be used. This effectively makes the parameter optional in the function call. When calling a function with default arguments, we have the option to either provide values for those arguments or omit them, in which case the default values will be used.

Q4. Assertion: A variable declared inside a function cannot be used outside it.

Reason: A variable created inside a function has a function scope.

Answer: (a) Both Assertion and Reason are true and Reason is the correct explanation of Assertion.

Explanation: Variables declared inside a function are typically local to that function, meaning they exist only within the scope of the function and they can only be accessed and used within the function in which they are declared.

Q5. Assertion: A variable not declared inside a function can still be used inside the function if it is declared at a higher scope level.

Reason: Python resolves a name using LEGB rule where it checks in Local (L), Enclosing (E), Global (G) and Built-in scopes (B), in the given order.

Answer: (a) Both Assertion and Reason are true and Reason is the correct explanation of Assertion.

Explanation: In Python, if a variable is not declared inside a function but is declared at a higher scope level (e.g., in the global scope or an enclosing scope), the function can still access and use that variable. Since Python follows the LEGB rule, variables declared at higher scope levels can be accessed within functions.

Q6. Assertion: A parameter having a default value in the function header is known as a default parameter.

Reason: The default values for parameters are considered only if no value is provided for that parameter in the function call statement.

Answer: (b) Both Assertion and Reason are true but Reason is not the correct explanation of Assertion.

Explanation: A default parameter is a parameter in a function definition that has a predefined value. When we call a function with default parameters, if we don't provide a value for a parameter, the default value specified in the function header will be used instead.

Q7. Assertion: A function declaring a variable having the same name as a global variable, cannot use that global variable.

Reason: A local variable having the same name as a global variable hides the global variable in its function.

Answer: (a) Both Assertion and Reason are true and Reason is the correct explanation of Assertion.

Explanation: Inside a function, you assign a value to a name which is already there in global scope, Python won't use the global scope variable because it is an assignment statement and assignment statement creates a variable by default in current environment. That means a local variable having the same name as a global variable hides the global variable in its function.

Question8.

Assertion: If the arguments in a function call statement match the number and order of arguments as defined in the function definition, such arguments are called positional arguments.

Reason: During a function call, the argument list first contains default argument(s) followed positional argument(s).

Answer: (c) Assertion is true but Reason is false.

Explanation: If the arguments in a function call statement match the number and order of arguments as defined in the function definition, such arguments are called positional arguments. During a function call, the argument list first contains positional argument followed by default arguments because any parameter cannot have a default value unless all parameters appearing on its right have their default values.

Type A: Short Answer Questions/Conceptual Questions

Q1. A program having multiple functions is considered better designed than a program without any functions. Why?

Ans. A program having multiple functions is considered better designed than a program without any functions because it makes program handling easier as only a small part of the program is dealt with at a time, thereby avoiding ambiguity. It reduces program size make the program more readable and understandable to a programmer thereby making program management much easier.

Q2. What all information does a function header give you about the function?

Ans. Function header is the first line of function definition that begins with keyword def and ends with a colon (:), specifies the name of the function and its parameters.

Q3. What do you understand by flow of execution?

Ans. Flow of execution refers to the order in which statements are executed during a program run.

Q4. What are arguments? What are parameters? How are these two terms different yet related? Give example.

Ans. Arguments — The values being passed through a function-call statement are called arguments.

Parameters — The values received in the function definition/header are called parameters.

Arguments appear in function call statement whereas parameters appear in function header. The two terms are related because the values passed through arguments while calling a function are received by parameters in the function definition.

For example:

def multiply(a, b):

print(a * b)

multiply(3, 4)

Here, a and b are parameters while 3, 4 are arguments.

Q5. What is the utility of: (i) default arguments, (ii) keyword arguments?

Ans. (i) Default arguments — Default arguments are useful in case a matching argument is not passed in the function call statement. They give flexibility to specify the default value for a parameter so that it can be skipped in the function call, if needed. However, still we cannot change the order of the arguments in the function call.

(ii) Keyword arguments — Keyword arguments are useful when you want to specify arguments by their parameter names during a function call. This allows us to pass arguments in any order, as long as we specify the parameter names when calling the function. It also makes the function call more readable and self-explanatory.

Q6. Explain with a code example the usage of default arguments and keyword arguments.

Ans. Default arguments — Default arguments are used to provide a default value to a function parameter if no argument is provided during the function call.

Output

Hello Alice

Hi there Bob

For example:

def greet(name, message="Hello"):

print(message, name)

greet("Alice")

greet("Bob", "Hi there")

In this example, the message parameter has a default value of "Hello". If no message argument is provided during the function call, the default value is used.

Output

Alice is 25 years old and lives in New York

Bob is 30 years old and lives in London

Hi there Bob

Keyword arguments — Keyword arguments allow us to specify arguments by their parameter names during a function call, irrespective of their position.

def person(name, age, city):

print(name, "is", age, "years old and lives in", city)

person(age=25, name="Alice", city="New York")

person(city="London", name="Bob", age=30)

In this example, the arguments are provided in a different order compared to the function definition. Keyword arguments specify which parameter each argument corresponds to, making the code more readable and self-explanatory.

Both default arguments and keyword arguments provide flexibility and improve the readability of code, especially in functions with multiple parameters or when calling functions with optional arguments.

Q7. Describe the different styles of functions in Python using appropriate examples.

Ans. The different styles of functions in Python are as follows:

Built-in functions: These are pre-defined functions and are always available for use.

Example:

name = input("Enter your name: ")

name_length = len(name)

print("Length of your name:", name_length)

In the above example, print(), len(), input() etc. are built-in functions.

User defined functions: These are defined by programmer.

Example:

def calculate_area(length, width):

area = length * width

return area

length = 5

width = 3

result = calculate_area(length, width)

print("Area of the rectangle:", result)

In the above example, calculate_area is a user defined function.

Functions defined in modules: These functions are pre-defined in particular modules and can only be used when corresponding module is imported.

Example:

import math

num = 16

square_root = math.sqrt(num)

print("Square root of", num, ":", square_root)

In the above example, sqrt is a function defined in math module.

Q8. Differentiate between fruitful functions and non-fruitful functions.

Ans.

Fruitful functions	Non-fruitful functions
Functions returning some value are called as fruitful functions.	Functions that do not return any value are called as non-fruitful functions.
They are also called as non-void functions.	They are also called as void functions.
They have return statements in the syntax: return<value>.	They may or may not have a return statement, but if they do, it typically appears as per syntax: return.
Fruitful functions return some computed result in terms of a value.	Non-fruitful functions return legal empty value of Python, which is None, to their caller.

Q9. Can a function return multiple values? How?

Ans. Yes, a function can return multiple values. To return multiple values from a function, we have to ensure following things:

1. The return statement inside a function body should be of the form:

return <value1/variable1/expression1>,<value2/variable2/expression2>,....

2. The function call statement should receive or use the returned values in one of the following ways:

(a) Either it receives the returned values in form a tuple variable.

(b) Or we can directly unpack the received values of tuple by specifying the same number of variables on the left-hand side of the assignment in function call.

Q10. What is scope? What is the scope resolving rule of Python?

Ans. Scope refers to part(s) of program within which a name is legal and accessible. When we access a variable from within a program or function, Python follows name resolution rule, also known as LEGB rule. When Python encounters a name (variable or function), it first searches the local scope (L), then the enclosing scope (E), then the global scope (G), and finally the built-in scope (B).

Q11. What is the difference between local and global variable?

Ans.

Local variable	Global variable
A local variable is a variable defined within a function.	A global variable is a variable defined in the 'main' program.
They are only accessible within the block in which they are defined.	They are accessible from anywhere within the program, including inside functions.
These variables have local scope.	These variables have global scope
The lifetime of a local variable is limited to the block of code in which it is defined. Once the execution exits that block, the local variable is destroyed, and its memory is released.	Global variables persist throughout the entire execution of the program. They are created when the program starts and are only destroyed when the program terminates.

Q12. When is global statement used? Why is its use not recommended?

Ans. If we want to assign some value to the global variable without creating any local variable then global statement is used. It is not recommended because once a variable is declared global in a function, we cannot undo the statement. That is, after a global statement, the function will always refer to the global variable and local variable cannot be created of the same name. Also, by using global statement, programmers tend to lose control over variables and their scopes.

Q13. Write the term suitable for following descriptions:

(a) A name inside the parentheses of a function header that can receive a value. Parameter

(b) An argument passed to a specific parameter using the parameter name. Keyword argument

(d) A value assigned to a parameter name in the function header. Default value

(e) A value assigned to a parameter name in the function call. Keyword argument

(f) A name defined outside all function definitions. Global variable

(g) A variable created inside a function body. Local variable

Q14. What do you understand by local and global scope of variables? How can you access a global variable inside the function, if function has a variable with same name?

Ans. Local scope — Variables defined within a specific block of code, such as a function or a loop, have local scope. They are only accessible within the block in which they are defined.

Global scope — Variables defined outside of any specific block of code, typically at the top level of a program or module, have global scope. They are accessible from anywhere within the program, including inside functions.

To access a global variable inside a function, even if the function has a variable with the same name, we can use the global keyword to declare that we want to use the global variable instead of creating a new local variable. The syntax is:

global<variable name>

For example:

def state1():

global tigers

tigers = 15

print(tigers)

tigers = 95

print(tigers)

state1()

print(tigers)

In the above example, tigers is a global variable. To use it inside the function state1 we have used global keyword to declare that we want to use the global variable instead of creating a new local variable.

Type B: Application Based Questions

Q1(a). What are the errors in following codes? Correct the code and predict output:

total = 0

def sum(arg1, arg2):

total = arg1 + arg2

print("Total :", total)

return total

sum(10, 20)

print("Total :", total)

Output

Total : 30

Total : 0

total = 0;

def sum(arg1, arg2): Ans.

total = arg1 + arg2;

print("Total :", total)

return total;

sum(10, 20);

print("Total :", total)

Explanation: There is an indentation error in second line. The return statement should be indented inside function and it should not end with semicolon. Function call should not end with semicolon.

def Tot(Number): #Method to find Total

Sum = 0

for C in range(1, Number + 1):

Sum += C

return Sum

print(Tot(3)) #Function Calls

print(Tot(6))

Q1(b). What are the errors in following codes? Correct the code and predict output:

def Tot(Number) #Method to find Total Ans.

Sum = 0

for C in Range (1, Number + 1):

Sum += C

RETURN Sum

print (Tot[3]) #Function Calls

print (Tot[6])

Output

Explanation: There should be a colon (:) at the end of the function definition line to indicate the start of the function block. Python's built-in function for generating sequences is range(), not Range().Python keywords like return should be in lowercase. When calling a function in python, the arguments passed to the function should be enclosed inside parentheses () not square brackets [].

Q2. Find and write the output of the following python code:

Answer Output

300 @ 200

300 @ 100

120 @ 100

300 @ 120

def Call(P = 40, Q = 20):

P = P + Q

Q = P - Q

print(P, '@', Q)

return P

R = 200

S = 100

R = Call(R, S)

print(R, '@', S)

S = Call(S)

print(R, '@', S)

Q3. Consider the following code and write the flow of execution for this. Line numbers have been given for your reference.

1. def power(b, p):

2. y = b ** p

3. return y

5. def calcSquare(x):

6. a = power(x, 2)

7. return a

9. n = 5

10. result = calcSquare(n)

11. print(result)

Ans. The flow of execution for the above program is as follows:

1 → 5 → 9 → 10 → 5 → 6 → 1 → 2 → 3 → 6 → 7 → 10 → 11

Click for Explanation

Q4. What will the following function return?

def addEm(x, y, z):

print(x + y + z)

Answer: The function addEm will return None. The provided function addEm takes three parameters x, y, and z, calculates their sum, and then prints the result. However, it doesn't explicitly return any value. In python, when a function doesn't have a return statement, it implicitly returns None. Therefore, the function addEm will return None.

Q5. What will the following function print when called?

def addEm(x, y, z):

return x + y + z

print(x + y + z)

Ans. The function addEm prints nothing when called.

Explanation: The function addEm(x, y, z) takes three parameters x, y, and z. It returns the sum of x, y, and z. Since the return statement is encountered first, the function exits immediately after returning the sum. The print statement after the return statement is never executed. Therefore, it prints nothing.

Answer: Output

Question 6(i) What will be the output of following program?

num = 1

def myfunc():

return num

print(num)

print(myfunc())

print(num)

Explanation: The code initializes a global variable num with 1. myfunc just returns this global variable. Hence, all the three print statements print 1.

Question 6(ii) What will be the output of following program?

Answer: Output

num = 1

def myfunc():

num = 10

return num

print(num)

print(myfunc())

print(num)

Explanation: num = 1 — This line assigns the value 1 to the global variable num.

def myfunc() — This line defines a function named myfunc.

print(num) — This line prints the value of the global variable num, which is 1.

print(myfunc()) — This line calls the myfunc function. Inside myfunc function, num = 10 defines a local variable num and assigns it the value of 10 which is then returned by the function. It is important to note that the value of global variable num is still 1 as num of myfunc is local to it and different from global variable num.

print(num) — This line prints the value of the global variable num, which is still 1.

Question 6(iii). What will be the output of following program?

Answer: Output

num = 1

def myfunc():

global num

num = 10

return num

print(num)

print(myfunc())

print(num)

Explanation: num = 1 — This line assigns the value 1 to the global variable num.

def myfunc() — This line defines a function named myfunc.

print(num) — This line prints the value of the global variable num, which is 1.

print(myfunc()) — This line calls the myfunc function. Inside the myfunc function, the value 10 is assigned to the global variable num. Because of the global keyword used earlier, this assignment modifies the value of the global variable num to 10. The function then returns 10.

print(num) — This line prints the value of the global variable num again, which is still 1.

Question 6(iv) What will be the output of following program?

Answer: Output

Hellothere!

def display():

print("Hello", end='')

display()

print("there!")

Explanation: The function display prints "Hello" without a newline due to the end='' parameter. When called, it prints "Hello". Outside the function, "there!" is printed on the same line due to the absence of a newline.

Q7. Predict the output of the following code:

a = 10

y = 5

def myfunc():

y = a

a = 2

print("y =", y, "a =", a)

print("a + y =", a + y)

return a + y

print("y =", y, "a =", a)

print(myfunc())

print("y =", y, "a =", a)

Answer

The code raises an error when executed.

Explanation : In the provided code, the global variables a and y are initialized to 10 and 5, respectively. Inside the myfunc function, the line a = 2 suggests that a is a local variable of myfunc. But the line before it, y = a is trying to assign the value of local variable a to local variable y even before local variable a is defined. Therefore, this code raises an UnboundLocalError.

Q8. What is wrong with the following function definition?

def addEm(x, y, z):

return x + y + z

print("the answer is", x + y + z)

Answer: In the above function definition, the line print("the answer is", x + y + z) is placed after the return statement. In python, once a return statement is encountered, the function exits immediately, and any subsequent code in the function is not executed. Therefore, the print statement will never be executed.

Q9. Write a function namely fun that takes no parameters and always returns None.

Answer

def fun():

return

Explanation

def fun():

return

r = fun()

print(r)

The function fun() returns None. When called, its return value is assigned to r, which holds None. Then print(r) outputs None.

Q10. Consider the code below and answer the questions that follow:

def multiply(number1, number2):

answer = number1 * number2

print(number1, 'times', number2, '=', answer)

return(answer)

output = multiply(5, 5)

(i) When the code above is executed, what prints out?

(ii) What is variable output equal to after the code is executed?

Ans. (i) When the code above is executed, it prints:

5 times 5 = 25

(ii) After the code is executed, the variable output is equal to 25. This is because the function multiply returns the result of multiplying 5 and 5, which is then assigned to the variable output.

Q11. Consider the code below and answer the questions that follow:

def multiply(number1, number2):

answer = number1 * number2

return(answer)

print(number1, 'times', number2, '=', answer)

output = multiply(5, 5)

(i) When the code above is executed, what gets printed?

(ii) What is variable output equal to after the code is executed?

Ans. (i) When the code above is executed, it will not print anything because the print statement after the return statement won't execute. Therefore, the function exits immediately after encountering the return statement.

(ii) After the code is executed, the variable output is equal to 25. This is because the function multiply returns the result of multiplying 5 and 5, which is then assigned to the variable output.

Q12(a). Find the errors in code given below:

def minus(total, decrement)

output = total - decrement

print(output)

return (output)

Ans. The errors in the code are:

def minus(total, decrement) # Error 1

output = total - decrement

print(output)

return (output)

There should be a colon at the end of the function definition line.

The corrected code is given below:

def minus(total, decrement):

output = total - decrement

print(output)

return (output)

Q12(b). Find the errors in code given below:

define check()

N = input ('Enter N: ')

i = 3

answer = 1 + i ** 4 / N

Return answer

Ans. The errors in the code are:

define check() #Error 1

N = input ('Enter N: ') #Error 2

i = 3

answer = 1 + i ** 4 / N

Return answer #Error 3

The function definition lacks a colon at the end.

The 'input' function returns a string. To perform arithmetic operations with N, it needs to be converted to a numeric type, such as an integer or a float.

The return statement should be in lowercase.

The corrected code is given below:

def check():

N = int(input('Enter N:'))

i = 3

answer = 1 + i ** 4 / N

return answer

Q12(c). Find the errors in code given below:

def alpha (n, string = 'xyz', k = 10) :

return beta(string)

return n

def beta (string)

return string == str(n)

print(alpha("Valentine's Day"):)

print(beta(string = 'true'))

print(alpha(n = 5, "Good-bye"):)

Ans. The errors in the code are:

def alpha (n, string = 'xyz', k = 10) :

return beta(string)

return n #Error 1

def beta (string) #Error 2

return string == str(n)

print(alpha("Valentine's Day"):) #Error 3

print(beta(string = 'true')) #Error 4

print(alpha(n = 5, "Good-bye"):) #Error 5

The second return statement in the alpha function (return n) is unreachable because the first return statement return beta(string) exits the function.

The function definition lacks colon at the end. The variable n in the beta function is not defined. It's an argument to alpha, but it's not passed to beta explicitly. To access n within beta, we need to either pass it as an argument or define it as a global variable.

There should not be colon at the end in the function call.

In the function call beta(string = 'true'), there should be argument for parameter n.

In the function call alpha(n = 5, "Good-bye"), the argument "Good-bye" lacks a keyword. It should be string = "Good-bye".

The corrected code is given below:

def alpha(n, string='xyz', k=10):

return beta(string, n)

def beta(string, n):

return string == str(n)

print(alpha("Valentine's Day"))

print(beta(string='true', n=10))

print(alpha(n=5, string="Good-bye"))

Q13. Draw the entire environment, including all user-defined variables at the time line 10 is being executed.

1. def sum(a, b, c, d):

2. result = 0

3. result = result + a + b + c + d

4. return result

6. def length():

7. return 4

9. def mean(a, b, c, d):

10. return float(sum(a, b, c, d))/length()

11.

12. print(sum(a, b, c, d), length(), mean(a, b, c, d))

Ans. The environment when the line 10 is being executed is shown below:

Draw the entire environment, including all user-defined variables at the time line 10 is being executed. Python Computer Science Sumita Arora Solutions CBSE Class 12

Q14. Draw flow of execution for the above program.

Ans. The flow of execution for the above program is as follows:

1 → 6 → 9 → 12 → 1 → 2 → 3 → 4 → 6 → 7 → 9 → 10 → 12

Line 1 is executed and determined that it is a function header, so entire function-body (i.e, lines 2, 3, 4) is ignored.Then line 6 is executed and determined that it is a function header, so entire function-body (i.e, line 7) is ignored, Line 9 is executed and determined that it is a function header, so entire function-body (i.e, line 10) is ignored. Then line 12 is executed and it has a function calls, so control jumps to the function header (line 1) and then first line of function-body, i.e, line 2, function returns after line 4 to function call line (line 12) and then control jumps to line 6, it is a function header and then first line of function-body, i.e., line 7, function returns after line 7 to function call line (line 12) and then control jumps to line 9, it is a function header and then first line of function-body, i.e., line 10, function returns after line 10 to function call line 12.

Q15. Find and write the output of the following python code:

a = 10

def call():

global a

a = 15

b = 20

print(a)

call()

Answer: Output : 15

Explanation

a = 10 — This line assigns the value 10 to the global variable a.

def call() — This line defines a function named call.

a = 15 — Inside the call function, this line assigns the value 15 to the global variable a. As global keyword is used earlier, this assignment modifies the value of the global variable a.

b = 20 — Inside the call function, this line assigns the value 20 to a local variable b.

print(a) — This line prints the value of the global variable a, which is 15. This is because we've modified the global variable a inside the call function.

Q16. In the following code, which variables are in the same scope?

def func1():

a = 1

b = 2

def func2():

c = 3

d = 4

e = 5

Ans. In the code, variables a and b are in the same scope because they are defined within the same function func1(). Similarly, variables c and d are in the same scope because they are defined within the same function func2(). e being a global variable is not in the same scope.

Q17. Write a program with a function that takes an integer and prints the number that follows after it. Call the function with these arguments:

Output

The print_number following 4 is 5

The print_number following 6 is 7

The print_number following 8 is 9

The print_number following 3 is 4

The print_number following -2 is -1

The print_number following -5 is -4

4, 6, 8, 2 + 1, 4 - 3 * 2, -3 -2

Ans.

1. def print_number(number):

2. next_number = number + 1

3. print("The number following", number, "is", next_number)

4. print_number(4)

5. print_number(6)

6. print_number(8)

7. print_number(2 + 1)

8. print_number(4 - 3 * 2)

9. print_number(- 3 - 2)

Explanation:

def print_number(number) — This line defines a function named print_number that takes one argument number.

next_number = number + 1 — Inside the print_number function, this line calculates the next number after the input number by adding 1 to it and assigns the result to the variable next_number.

print("The number following", number, "is", next_number) — Inside the print_number function, this line prints a message stating the number and its following number.

Then the print_number function is called multiple times with 4, 6, 8, 3 ,((4 - 3 * 2) = -2), ((-3-2) = -5) as arguments.

Q18. Write a program with non-void version of above function and then write flow of execution for both the programs.

Ans. The non-void version of above code is as shown below:

Output

-1

-4

1. def print_number(number):

2. next_number = number + 1

3. return next_number

4. print(print_number(4))

5. print(print_number(6))

6. print(print_number(8))

7. print(print_number(2 + 1))

8. print(print_number(4 - 3 * 2))

9. print(print_number(-3 - 2))

Explanation:

def print_number(number) — This line defines a function named print_number that takes one argument number.

next_number = number + 1 — Inside the print_number function, this line calculates the next number after the input number by adding 1 to it and assigns the result to the variable next_number.

return next_number — Inside the print_number function, this line returns next_number.

Then the print_number function is called multiple times with 4, 6, 8, 3 ,((4 - 3 * 2) = -2), ((-3-2) = -5) as arguments.

The flow of execution for the above program with non-void version is as follows:

1 → 4 → 1 → 2 → 3 → 4 → 5 → 1 → 2 → 3 → 5 → 6 → 1 → 2 → 3 → 6 → 7 → 1 → 2 → 3 → 7 → 8 → 1 → 2 → 3 → 8 → 9 → 1 → 2 → 3 → 9

Line 1 is executed and determined that it is a function header, so entire function-body (i.e., line 2 and 3) is ignored. Then line 4 is executed and it has function call, so control jumps to the function header (line 1) and then to first line of function-body, i.e., line 2, function returns after line 3 to line containing function call statement i.e., line 4. The next lines 5, 6, 7, 8, 9 have function calls so they repeat the above steps.

The flow of execution for the void version program is as follows:

1 → 4 → 1 → 2 → 3 → 4 → 5 → 1 → 2 → 3 → 5 → 6 → 1 → 2 → 3 → 6 → 7 → 1 → 2 → 3 → 7 → 8 → 1 → 2 → 3 → 8 → 9 → 1 → 2 → 3 → 9

Q19(i). What is the output of following code fragments?

Output

[1, 2, 3, [4]] [1, 2, 3, [4]]

def increment(n):

n.append([4])

return n

L = [1, 2, 3]

M = increment(L)

print(L, M)

Answer

Explanation: In the code, the function increment appends [4] to list n, modifying it in place. When L = [1, 2, 3], calling increment(L) changes L to [1, 2, 3, [4]]. Variable M receives the same modified list [1, 2, 3, [4]], representing L. Thus, printing L and M results in [1, 2, 3, [4]], confirming they reference the same list. Therefore, modifications made to list inside a function affect the original list passed to the function.

Q19(ii). What is the output of following code fragments?

Answer: Output

[23, 35, 47, [49]]

23 35 47 [49]

True

def increment(n):

n.append([49])

return n[0], n[1], n[2], n[3]

L = [23, 35, 47]

m1, m2, m3, m4 = increment(L)

print(L)

print(m1, m2, m3, m4)

print(L[3] == m4)

Explanation : The function increment appends [49] to list n and returns its first four elements individually. When L = [23, 35, 47], calling increment(L) modifies L to [23, 35, 47, [49]]. Variables m1, m2, m3, and m4 are assigned the same list [23, 35, 47, [49]], representing the original list L. Thus, printing L and m1, m2, m3, m4 yields [23, 35, 47, [49]]. The expression L[3] == m4 evaluates to True, indicating that the fourth element of L is the same as m4.

Q20. What will be the output of the following Python code?

V = 25

def Fun(Ch):

V = 50

print(V, end = Ch)

V *= 2

print(V, end = Ch)

print(V, end = "*")

Fun("!")

print(V)

25*50!100!25

50*100!100!100

25*50!100!100

Error

Answer

25*50!100!25

Explanation

V = 25 — initializes global variable V to 25.

print(V, end = "*") — Prints the global variable V (25) followed by an asterisk without a newline.

Fun("!") — Calls the function Fun with the argument "!".

Inside function Fun, V = 50 initializes a local variable V within the function with the value 50. This variable is different from the global variable V that has the value 25.

print(V, end = Ch) — Prints the local variable V (50) followed by the character passed as an argument to the function, which is "!".

V *= 2 — Multiplies the local variable V (50) by 2, making it 100.

print(V, end = Ch) — Prints the updated local variable V (100) followed by the character "!".

The function Fun returns and the line print(V) is executed. It prints the global variable V without any newline character. The global variable V remains unchanged (25).

#######################################################################

1. What is the default return value for a function that does not return any value explicitly?

(a) None (b) int (c) double (d) null

2. Which of the following items are present in the function header?

(a) Function name only (b) Both function name and parameter list

3. Which of the following keywords marks the beginning of the function block?

(a) Func (b) define (d) def (d) function

4. What is the name given to that area of memory, where the system stores the parameters and local variable of a function call?

(a) Heap (b) storage area (c) a stack (d) an array

5. Pick one the following statements to correctly complete the function body in the given code snippet.

Def f(number):

#Missing function body

Print(f(5))

(a) Return “number” (b) print(number) (c) print(“number”) (d) return number

6. Which of the following function headers is correct?

7. Which of the following statements is not true for parameter passing to function?

8. Which of the following function calls can be used to invoke the below function definition?

9. Which of the following function calls will cause Error while invoking the below function definition?

10. What is a variable defined outside all the functions referred to as?

(a) A static variable (b) A global variable

11. What is a variable defined inside a function referred to as

(a) A static variable (b) A global variable

12. Carefully observe the code and give the answer.

13. What is the result of this code?

14. What is the order of resolving scope of a name in a Python program?

15. Which of the given argument type can be skipped form a function call?

Fill in the Blanks

1. A________is a subprogram that acts on data and often returns a value.

2. Python names the top level segment (main program) as _________.

3. In Python, program execution begins with first statement of ______segment.

4. The values being passed through a function-call statement are called_____.

5. The values received in the function definition/header are called________.

6. A parameter having default value in the function header is known as a_______.

tion ?

7. A ________ argument can be skipped in the function call statement.

8.__________ arguments are the named arguments with assigned values being passed in the function call statement.

9. A void function also returns a _______value to its caller.

10. By default, Python names the segment with top-level statements (main program) as_________.

11. The ________refers to the order in which statements are executed during a program run.

12. The default value for a parameter is defined in function_________.

True/False Questions

1. Non-default arguments can be placed before or after a default argument in a function definition.

2. A parameter having default value in the function header is known as a default parameter.

3. The first line of function definition that begins with keyword def and ends with a colon (:), is also known as function header.

4. Variables that are listed within the parentheses of a function header are called function variables.

5. In Python, the program execution begins with first statement of _main_ segment.

6. Default parameters cannot be skipped in function call.

7. The default values for parameters are considered only if no value is provided for that parameter in the function call statement.

8. A python function may return multiple values.

9. A void function also returns a value i.e., None to it called.

10. Variable defined inside functions can have global scope.

11. A local variable having the same name as that of a global variable hides the global variable in its function.

COMPUTER SCIENCE WITH Pre

Assignment

Type A Short Answer Questions/Conceptual Questions

1. A program having multiple functions is considered better designed than without any functions. Why?

2. What all information does a function header give you about the function ? & What do you understand by flow of execution?

4. What are arguments? What are parameters? How are these two terms different yet related t 10 default arguments, (i) keyword arguments ? & What is the utility of

Explain with a code example the usage of default arguments and keyword argument 7. Describe the different styles of functions in Python using appropriate examples

& Differentiate between fruitful functions and non-fruitful functions

Can a function return multiple values? How?

18 What is scope 7 What is the scope resolving rule of Python?

11. What is the difference between local and global variables?

12. When is global statement used? Why is its use not recommended?

13. Write the term suitable for following descriptions:

(a) A name inside the parentheses of a function header that can receive a value. (b) An argument passed to a specific parameter using the parameter name.

(4) A value assigned to a parameter name in the function header.

(e) A value assigned to a parameter name in the function call.

A name defined outside all function definitions

(g) A variable created inside a function body

14. What do you understand by local and global scope of variables? How can you access a global variable the function, if function has a variable with same name.

Type B: Application Based Questions

(CBSE Sample Paper 20

1. What are the errors in following codes ? Correct the code and predict output:

(a) total = 0;

def sum( arg1, arg2):

total

arg1+ arg2;

print("Total:", total)

return total;

Chapter 3

2. Find

sum( 10, 20);

print("Total", total)

(b)

def Tot (Number)

#Method to find Total

Sum-8

for C in Range (1, Number + 1):

Sum + C

RETURN Sum

print (Tot[3])

#Function Calls

print (Tot[6])

CBSE D 2015

Dfgdgdgdgdgd

Type C: Programming Practice/Knowledge based Questions

1. Write a function that takes amount-in-dollars and dollar-to-rupee conversion price; it then returns the amount converted to rupees. Create the function in both void and non-void forms.

2. Write a function to calculate volume of a box with appropriate default values for its parameters. Your function should have the following input parameters:

(a) length of box;

(b) width of box;

Test it by writing complete program to invoke it.

3. Write a program to have following functions:

(i) a function that takes a number as argument and calculates cube for it. The function does not return a value. If there is no value passed to the function in function call, the function should calculate cube of 2.

(ii) a function that takes two char arguments and returns True if both the arguments are equal otherwise False.

Test both these functions by giving appropriate function call statements.

4. Write a function that receives two numbers and generates a random number from that range. Using this function, the main program should be able to print three numbers randomly.

5. Write a function that receives two string arguments and checks whether they are same-length strings (returns True in this case otherwise False).

6. Write a function namely nthRoot() that receives two parameters x and n and returns nth root of x i.e., The default value of n is 2.

7. Write a function that takes a number n and then returns a randomly generated number having exactly n digits (not starting with zero) e.g., if n is 2 then function can randomly return a number 10-99 but 07, 02 etc. are not valid two digit numbers.

8. Write a function that takes two numbers and returns the number that has minimum one's digit. [For example, if numbers passed are 491 and 278, then the function will return 491 because it has got minimum one's digit out of two given numbers (491's 1 is < 278's 8)].

9. Write a program that generates a series using a function which takes first and last values of the series and then generates four terms that are equidistant e.g., if two numbers passed are 1 and 7 then function returns 13 5 7.

Question100

Question3 Explanation [back to question]

Line 1 is executed and determined that it is a function header, so entire function-body (i.e., lines 2 and 3) is ignored. Line 5 is executed and determined that it is a function header, so entire function-body (i.e., lines 6 and 7) is ignored. Lines 9 and 10 are executed, line 10 has a function call, so control jumps to function header (line 5) and then to first line of function-body, i.e., line 6, it has a function call , so control jumps to function header (line 1) and then to first line of function-body, i.e, line 2. Function returns after line 3 to line 6 and then returns after line 7 to line containing function call statement i.e, line 10 and then to line 11.

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