Iterate over characters of a string in Python

In Python, while operating with String, one can do multiple operations on it. Let’s see how to iterate over the characters of a string in Python.

Example #1: Using simple iteration and range() 

g e e k s f o r g e e k s 

G
E
E
K
S

Code #1

• Time complexity: O(n), where n is the length of the string.
• Auxiliary space: O(1)

Code #2

• Time complexity: O(n), where n is the length of the string.
• Auxiliary space: O(1),

Example #2: Using enumerate() function 

G
e
e
k
s

Time complexity: O(n) where n is the length of the string

Auxiliary space: O(1).

Example #3: Iterate characters in reverse order 

S K E E G 

s
k
e
e
g
r
o
f
s
k
e
e
g

Example #4: Iteration over particular set of element. Perform iteration over string_name by passing particular string index values. 

g e e k s f o r

Example #5: Iterate characters using itertools

Alternatively, you can use the islice() function from itertools to iterate over the characters of a string. islice() returns an iterator that returns selected elements from the input iterator, allowing you to specify the start and end indices of the elements you want to iterate over. Here’s an example of how you can use islice() to iterate over the characters of a string:

h
e
l
l
o

Time complexity: O(n)
Auxiliary Space: O(n)

Example #6: Using map() function 

Approach: 

• Initialize string. 
• define a function that will print each character of the string in iteration. 
• Using map function on a string. 
• Since the map function applied function to each item in iterable in the loop and returns a new iterator that yields transformed on demand. 

g
e
e
k
s

Time Complexity: O(N). Here N is the length of the string. 
Auxiliary Space: O(1). Since no extra space is required.