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()
Python3
# Python program to iterate over characters of a string# Code #1string_name = "neveropen"# Iterate over the stringfor element in string_name: print(element, end=' ')print("\n")# Code #2string_name = "GEEKS"# Iterate over indexfor element in range(0, len(string_name)): print(string_name[element]) |
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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
Python3
# Python program to iterate over characters of a stringstring_name = "Geeks"# Iterate over the stringfor i, v in enumerate(string_name): print(v) |
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
Python3
# Python program to iterate over characters of a string# Code #1string_name = "GEEKS"# slicing the string in reverse fashionfor element in string_name[ : :-1]: print(element, end =' ')print('\n')# Code #2string_name = "neveropen"# Getting length of stringran = len(string_name)# using reversed() functionfor element in reversed(range(0, ran)): print(string_name[element]) |
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Example #4: Iteration over particular set of element. Perform iteration over string_name by passing particular string index values.
Python3
# Python program to iterate over particular set of element.string_name = "neveropen"# string_name[start:end:step]for element in string_name[0:8:1]: print(element, end =' ') |
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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:
Python3
import itertoolsstring = "hello"# Create an iterator that returns the characters from index 1 to the end of the stringchar_iter = itertools.islice(string, 0, None)# Iterate over the selected charactersfor char in char_iter: print(char)#This code is contributed by Edula Vinay Kumar Reddy |
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.
Python
# Python program to iterate over character# of string in pythonstring_name = "Lazyroar"def h(x): print(x)# Using map functionk = map(h, string_name)for _ in k: pass |
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.
