How to Iterate over a List

Python : How to Iterate over a List ?

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Lists are similar to dynamically sized arrays, which are declared in other languages(e.g., vector in C++ and ArrayList in Java). Lists do not have to be homogeneous all of the time, which makes it a very useful tool in Python. DataTypes such as Integers, Strings, and Objects can all be included in a single list. Lists are mutable, which means they can be changed after they’ve been created.

We’ll look at a few different ways to iterate through a list in this article.

Examples:

Input:

givenlist=['hello' , 'world' , 'this', 'is' ,'python']

Output:

hello 
world
this 
is 
python

Print the list by iterating through it

There are several ways to iterate through a list some of them are:

Method #1 : Using For loop

We can use for loop to iterate over the list.

Below is the implementation:

# Given list
givenlist=['hello' , 'world' , 'this', 'is' ,'python']

#Using for loop to iterate over the list
for element in givenlist:
    print(element)

Output:

hello 
world
this 
is 
python

Method #2 :Using while loop

In Python, the while loop is used to iterate through a block of code as long as the test expression (condition) is true. This loop is typically used when we don’t know how many times to iterate ahead of time.

Here the condition is loop till length of list

Below is the implementation:

# Given list
givenlist = ['hello', 'world', 'this', 'is', 'python']

# Getting length of list
length = len(givenlist)

# Initializing position to index 0
position = 0

# Iterating using while loop
while position < length:
    print(givenlist[position])
    position = position + 1

Output:

hello 
world
this 
is 
python

Method #3: Using For loop and range() function

If we want to use the standard for loop, which iterates from x to y, we can do so.

Below is the implementation:

# Given list
givenlist = ['hello', 'world', 'this', 'is', 'python']

# Getting length of list
length = len(givenlist)

# Iterating till length of list
for index in range(length):
    print(givenlist[index])

Output:

hello 
world
this 
is 
python

Method #4 : Using list comprehension

We can iterate over the list in one line using list comprehension

Below is the implementation:

# Given list
givenlist = ['hello', 'world', 'this', 'is', 'python']

# Using list comprehension
[print(i) for i in givenlist]

Output:

hello 
world
this 
is 
python

Method #5 :Using enumerate()

The enumerate() function can be used to transform a list into an iterable list of tuples or to get the index based on a condition check.

Below is the implementation:

# Given list
givenlist = ['hello', 'world', 'this', 'is', 'python']

# Using enumerate()
for index, value in enumerate(givenlist):
    print(value)

Output:

hello 
world
this 
is 
python

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