All about Functions

Question 1

What keyword is used in python to define a function?

Answer 1

1. def
2. Example = def my_introduction():

Question 2

What will be the output of the following function if it was invoked?

def my\_function():
print('Hello World')

Answer 2

It would result in a IndentationError

Question 3

True or False:

Custom function names in python can start with a digit.

Answer 3

False

1. Functions can start with either an underscore of a letter.
2. The letter can be uppercase or lowercase
3. Digits can be included after letters or the underscore

Question 4

1. Explain what is happening with the line “hi_function = my_function”

def my\_function():
 print('Hello World')

hi_function = my_function

Answer 4

1. Functions can be treated as objects
2. hi_function is a variable which has a reference to the original function
3. You can use either name to invoke the function.

Question 5

What type of scope do the following variables have?

**name = 'Bryce'
city = 'Toronto'**

def introduction():
print(‘Hi my name is: ‘ , name)
print(‘I live in : ‘ , city)

Answer 5

1. Both variables have global scope
2. Variables declared with global scope can be accessed by functions

Question 6

How would you refer to the name variable on line 1.

1. def introduction(name):
   print(“Hello, my name is “ , name)

Answer 6

1. Input argument

Question 7

What will be the output when the following function is called

def my\_introduction():
 print("Hello, my name is John")

my_introduction(‘Ted’)

Answer 7

1. This would result in a TypeError as you’re trying to pass an argument to a function which doesn’t except an input argument.

Question 8

True of False:

Input arguments passed into functions are limited to certain data types.

Answer 8

1. False
2. Input arguments can be of any data type, such as floats, ints, lists etc

Question 9

When using multiple return values in a function, what is returned?

def add\_state(x,y):
 add\_result = x + y
 sub\_result = x - y

return add_result, sub_result

Answer 9

The function will return a tuple with the values as fields of the tuple.

Question 10

maths = 100 is an example of what?

total_score(math=100, physics=56, chemistry=34, biology=99)

Answer 10

1. A keyword argument
2. Allows you to specify input arguments by name while invoking functions.

Question 11

True or False

Python allows you to mix positional and keyword arguments to invoke a function.

Answer 11

1. True
2. However, the order does matter.

This will work:

total_score(100,56, chemistry=34, biology=99)

This will result in an SyntaxError

total_score(maths =100,56, chemistry=34, biology=99)

Question 12

When invoking a function, do keyword arguments have to be in the correct order?

Answer 12

1. No
2. For example, this code is correct.

def total\_score(math, physics, chemistry, biology):
 print(math, physics, chemistry, biology)

total_score(biology=99, math=50, physics=89, chemistry=90)

Question 13

What does *args do when used in functions?

Answer 13

*args indicates that the function can be invoked with any number of arguments.

def print_fn(*args):

Question 14

Using the example below, what is **kwargs

def student_details(**kwargs)

Answer 14

1. It stands for keyword variable length arguments

Question 15

When you use **kwargs, what datatype does python pack the arguments into?

Answer 15

1. Python packs the variable length arguments into a dictionary, not a tuple.

Question 16

Which of the following are valid types of arguments in Python?

1. Variable length arguments
2. Ordered arguments
3. Default arguments
4. Keyword arguments

Answer 16

Correct answers are highlighted.

1. Variable length arguments
2. Ordered arguments
3. Default arguments
4. Keyword arguments

Question 17

Which of the following are valid function names in Python?

1. functionName()
2. -functionName()
3. _function_name()
4. 123_Function_Name()
5. _123_Function_Name()

Answer 17

1. functionName()
2. -functionName()
3. _function_name()
4. 123_Function_Name()
5. _123_Function_Name()

Question 18

What does this function indicate?

def some\_fn(a,b,c=True):
 print(a,b,c)

1. a and b are optional arguments, c is required
2. a and b are string arguments, c is boolean
3. a and b are numeric arguments, c is boolean
4. a and b are required arguments, c is optional

Answer 18

a and b are required arguments, c is optional

Question 19

Which of the following statements about the data types of return values is/are false?

1. A return statement is mandatory in functions
2. A function in Python can return a dictionary
3. A function in Python can return nothing
4. A function in Python may have no return statement

Answer 19

A return statement is mandatory in functions

Question 20

Which of the following function definitions allows the function to accept variable length arguments?

1. some_fn(…args)
2. some_fn(…)
3. some_fn(*)
4. some_fn(*args)

Answer 20

some_fn(*args)

Question 21

Which of the following statements about functions is false?

1. Functions can have different names
2. Functions are invoked using parenthesis
3. Functions can contain any number of statements in the function body
4. Function cannot access variables which are declared outside the function

Answer 21

Function cannot access variables which are declared outside the function

Question 22

What is the default return value from a function when no return statement is specified?

1. ’’’
2. 0
3. -1
4. None

Answer 22

None

Question 23

Which of the following statements about positional arguments to function is/are true?

1. A function can accept any number of positional arguments
2. They can be of any data type