Functions

Question 1

What is len()

Give example code

Answer 1

Checks for length
st = ‘Print every word in this sentence that has an even number of letters’

for word in st.split():
    if len(word) %2 == 0:
        print(word + ' ')

Question 2

What is the range() function?

Give example code

Answer 2

A range() function returns a sequence of numbers, instead of having to write out a long list yourself like: numlist = [1, 2, 3,4,5,6]

You can instead just do:

for x in range(6):
–print (x)

OUTPUT 
0
1
2
3
etc...

Question 3

What is the zip function?

Give example code

Answer 3

A zip function basically compresses two lists together

adj = ["red", "big", "tasty"]
fruits = ["apple", "banana", "pear"]

for item in zip(adj, fruits):
print(item)
print(‘\n’)

OUTPUT
(‘red’, ‘apple’)

(‘big’, ‘banana’)

(‘tasty’, ‘pear’)

Question 4

What is a function in Python?

Give an example

Answer 4

A function is a group of related statements that performs a specific task you want.

Functions are objects in which we organise our code help and break a program into smaller chunks of reusable code.

Example:

def function_name(parameters):
	"""docstring""" # The first statement in the body of a function is usually a string, which can be accessed with function_name.\_\_doc\_\_
	statement(s)

Question 5

What is the difference between a keyword and a function?

Give example code

Answer 5

Generally speaking, in any language,

A function is a set of instructions that are to be executed when the function is called.

A keyword has predefined meaning in the compiler.

To make things easier, simply assume, that a keyword is an instance of some function that is already defined in the compiler.

Question 6

What is the return statement?

Give example

Answer 6

The return statement is used to exit a function and go back to the place from where it was called.

def absolute_value(num):
    """This function returns the absolute
    value of the entered number"""

if num >= 0:
    return num
else:
    return -num

print(absolute_value(2))

print(absolute_value(-4))

OUTPUT

2
4

Question 7

What does list() do?

Give example

Answer 7

returns a list:

# empty list
print(list())

# vowel string
vowel_string = 'aeiou'
print(list(vowel_string))

# vowel tuple
vowel_tuple = ('a', 'e', 'i', 'o', 'u')
print(list(vowel_tuple))

# vowel list
vowel_list = ['a', 'e', 'i', 'o', 'u']
print(list(vowel_list))

Question 8

What does abs() do?

Answer 8

x = abs(3+5j)

Question 9

What does sum() do?

Answer 9

numbers = [2.5, 3, 4, -5]

numbers_sum = sum(numbers, 10)
print(numbers_sum)

Question 10

Whats the difference between sum() and abs()?

Answer 10

sum() can process strings while abs() can do complex numbers