for ch in string python

Iterating each character in a string using Python

stackoverflow.com › questions › 538346 › iterating-each-character-in-a-string-using-python

As Johannes pointed out,

for c in "string":
    #do something with c

You can iterate pretty much anything in python using the for loop construct,

for example, open("file.txt") returns a file object (and opens the file), iterating over it iterates over lines in that file

with open(filename) as f:
    for line in f:
        # do something with line

If that seems like magic, well it kinda is, but the idea behind it is really simple.

There's a simple iterator protocol that can be applied to any kind of object to make the for loop work on it.

Simply implement an iterator that defines a next() method, and implement an __iter__ method on a class to make it iterable. (the __iter__ of course, should return an iterator object, that is, an object that defines next())

See official documentation

Answer from hasen on Stack Overflow

Stack Overflow

stackoverflow.com › questions › 538346 › iterating-each-character-in-a-string-using-python

Iterating each character in a string using Python - Stack Overflow

Top answer

1 of 9

530

As Johannes pointed out,

for c in "string":
    #do something with c

You can iterate pretty much anything in python using the for loop construct,

for example, open("file.txt") returns a file object (and opens the file), iterating over it iterates over lines in that file

with open(filename) as f:
    for line in f:
        # do something with line

If that seems like magic, well it kinda is, but the idea behind it is really simple.

There's a simple iterator protocol that can be applied to any kind of object to make the for loop work on it.

Simply implement an iterator that defines a next() method, and implement an __iter__ method on a class to make it iterable. (the __iter__ of course, should return an iterator object, that is, an object that defines next())

See official documentation

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349

If you need access to the index as you iterate through the string, use enumerate():

for index, character in enumerate('test'):
    print(index, character)
... 
0 t
1 e
2 s
3 t

Python Iterate Over String

Python iterate over each string?

string - How to iterate through characters and lines in Python?

python - Iterate over character in string with index

Behaviour of Python when attempting to iterate over characters in a string

More results from stackoverflow.com

GeeksforGeeks

geeksforgeeks.org › python › iterate-over-characters-of-a-string-in-python

Iterate over characters of a string in Python - GeeksforGeeks

July 11, 2025 - In this article, we will learn ... in Python. There are several methods to do this, but we will focus on the most efficient one. The simplest way is to use a loop. Let’s explore this approach. The simplest way to iterate over the characters in a string is by using a for ...

Discussions

python - result = [ch for ch in string if (ch != ' ')]; result = str(result); print(result); prints list, not string - Stack Overflow

The for loop within this list takes each value from the string, one at a time, and places it into the list - this is why the list ['a', 'b', 'c'] appears in your code. To obtain a string without spaces from a string with spaces: Copystring = 'a b c' # obtain characters from the string that ... More on stackoverflow.com

stackoverflow.com

How do you make a program iterate over a string (which is already a variable) a set amount of times?

It is a bit hard to understand what you are asking. I think I am misundertanding. But here is how to iterate over a string X amount of times: iter_times = 5 my_str = "abcdefg" for i in range(iter_times): for char in my_str: print(char) If you just want the index of the character while you are iterating, you can use enumerate: my_str = "abcdefg" for i, char in enumerate(my_str): print(f"{char} has position {i} in my_str") More on reddit.com

r/learnpython

27

2

March 6, 2024

Not really understanding when to use for I in string vs for I in range(len(string))

For strings, there is basically zero reason to use the latter. If you need access to the index, use enumerate. For lists, you use the latter when you are changing the list that you're iterating over. More on reddit.com

r/learnpython

14

8

September 27, 2020

Using while loops to find a character in a string

s = "abcdef" currIndex = 0 length = len(s) while currIndex < length: if s[currIndex] == 'e': print(currIndex) currIndex += 1 create an index variable (currIndex) set to the starting point of the string, 0. create a limit variable for your index (length), in this case the limit is the length of the string. set your while loop to execute as long as currIndex is less than the limit. keep in mind the length of the string will always be one higher than the last index..hense "<" instead of "<=". the first character is at index 0, and the last is at len(s)-1. each iteration of the while loop checks if the character of s at currIndex is equal to the char you're looking for and prints currIndex if it is. increment currIndex by 1 More on reddit.com

r/learnprogramming

6

1

December 20, 2022

Videos

12:25

YouTube

Accessing String Characters in Python - YouTube

March 3, 2023

youtube.com

How to Iterate over a String in Python - YouTube

May 24, 2025

10:51

YouTube

for Loop with Strings in Python - YouTube

How To Check A String For A Character In Python - YouTube

How To Iterate Through A String In Python - YouTube

runestone.academy › ns › books › published › fopp › Iteration › Stringsandforloops.html

7.4. Strings and for loops — Foundations of Python Programming

Note that the for loop processes the characters in a string or items in a sequence one at a time from left to right. ... Iteration by item will process once for each item in the sequence. ... The blank is part of the sequence. ... Yes, there are 12 characters, including the blank. Error, the for statement needs to use the range function. The for statement can iterate over a sequence item by item. How many times is the word HELLO printed by the following statements? s = "python rocks" for ch in s[3:8]: print("HELLO")

Stack Overflow

stackoverflow.com › questions › 62774032 › result-ch-for-ch-in-string-if-ch-result-strresult-printresul

python - result = [ch for ch in string if (ch != ' ')]; result = str(result); print(result); prints list, not string - Stack Overflow

Top answer

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str() on a list does not magically turn said list into a no delimiter string. When you do str(['a', 'b', 'c']) - what you actually get is '['a', 'b', 'c']', which is indeed a string.

If you'd like the result to be 'abc' please, use .join.

''.join(['a', 'b', 'c'])

Output-

'abc'

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1

Here result = [ch for ch in string if (ch != ' ')] you eliminate spaces and save the chars into list. But to have string again, you need to join them:

string = 'a b c'

result = [ch for ch in string if (ch != ' ')]

s = "".join(result)

print(s)  # abc

Here is the related doc page.

Spark By {Examples}

sparkbyexamples.com › home › python › how to iterate a string in python using for loop

How to Iterate a String in Python using For Loop - Spark By {Examples}

May 21, 2024 - How to iterate a string in Python using For loop? You can iterate over each character of a string using multiple ways of Python. The string is a basic

Gitbooks

buzzcoder.gitbooks.io › codecraft-python › content › string › loop-through-a-string.html

Loop through a string · CodeCraft-Python - BuzzCoder

The len() function is a Python built-in function that reports the size, or length, of its input, which is usually a string or a list. s = 'Apple pie' print(len(s)) # 9 print(len('Banana float')) # 12 len('') # 0 (an empty string) print(len('donuts') + len('pan cake')) # 14 · Here we show two ways to iterate over characters in a string: One way to iterate over a string is to use for i in range(len(str)):. In this loop, the variable i receives the index so that each character can be accessed using str[i].

Stanford CS

cs.stanford.edu › people › nick › py › python-string.html

Python Strings

Each character in a Python string is a unicode character, so characters for all languages are supported.

Find elsewhere

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reddit.com › r/learnpython › how do you make a program iterate over a string (which is already a variable) a set amount of times?

r/learnpython on Reddit: How do you make a program iterate over a string (which is already a variable) a set amount of times?

March 6, 2024 -

I'm new to python and one of the exercises they gave us at school requires me to make the program iterate over a string a set amount of times.

The issue is that if I use the "for" loop (aka: for i in range()), there is nowhere to put which variable I want it to iterate over, and if I put "for i in (variable)", I can't tell it how many times it needs to do it and just ends up iterating the whole string. Any input on the matter is appreciated.

Top answer

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5

It is a bit hard to understand what you are asking. I think I am misundertanding. But here is how to iterate over a string X amount of times: iter_times = 5 my_str = "abcdefg" for i in range(iter_times): for char in my_str: print(char) If you just want the index of the character while you are iterating, you can use enumerate: my_str = "abcdefg" for i, char in enumerate(my_str): print(f"{char} has position {i} in my_str")

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2

Depends on what exactly you need to do with the string

Dot Net Perls

dotnetperls.com › for-python

Python - for: Loop Over String Characters - Dot Net Perls

January 4, 2025 - Tip If you need to get adjacent characters, or test many indexes at once, the for-loop that uses range() is best. s = "abc" # Loop over string. for c in s: print(c) # Loop over string indexes.

W3Schools

w3schools.com › python › gloss_python_for_string.asp

Python For Looping Through a String

Remove List Duplicates Reverse a String Add Two Numbers · Python Examples Python Compiler Python Exercises Python Quiz Python Challenges Python Practice Problems Python Server Python Syllabus Python Study Plan Python Interview Q&A Python Training ... Python For Loops Tutorial For For Break For Continue Looping Through a Range For Else Nested Loops For pass

LaunchCode

education.launchcode.org › lchs › chapters › loops › iterating-over-collections.html

6.5. Loop Through a String — LaunchCode's LCHS documentation

In the for statement, a string (or a variable containing a string) replaces range. The first time the loop runs, the loop variable gets assigned the first character in the string (character = 'H' or char = 'T'). Each time the loop repeats, the variable holds the next character in the string.

Quora

quora.com › How-do-you-iterate-over-the-characters-of-a-string-in-Python

How to iterate over the characters of a string in Python - Quora

Answer (1 of 5): Very simply : [code]>>> my_string = 'This is my string' >>> for character in my_string: ... print(character) T h i s i s m y s t r i n g [/code]if you need to record the character and the index, you can use enumerate : [code]>>> my_string = 'This is my string' >>> for...

reddit.com › r/learnpython › not really understanding when to use for i in string vs for i in range(len(string))

r/learnpython on Reddit: Not really understanding when to use for I in string vs for I in range(len(string))

September 27, 2020 -

Just looking for clarification for this very simple thing. Please correct me if I’m wrong but from what I understand, in for i in string, it takes each element in the string over the entire length. For i in range(len(string)) it indexes the elements and looks at the elements at each index so at position 0, string =‘x’ and at 1 string= ‘d’ ect.

If this is correct, I’m afraid I still don’t see the difference by way of when to use each or what purpose they serve.

Top answer

1 of 5

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For strings, there is basically zero reason to use the latter. If you need access to the index, use enumerate. For lists, you use the latter when you are changing the list that you're iterating over.

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Let's do this with code, since your words aren't particularly clear without reference to some specific examples: s = 'abcdefg' for character in s: print(character) for i in range(len(s)): character = s[i] print(character) Both loops above produce the same printed output (each character of the string 's' on its own line). The first loop iterates over the characters of 's' directly; there is no indexing used. The second loop iterates over a sequence of indices (created by the range() iterable), and uses those indices to look up the character. Now, do you have any specific question(s) about the above two examples, and how they differ? The first loop is a newer form of looping that didn't exist in the original Python 1, but is now preferred for this particular usage. The second form has existed for longer, and still works, just requires the extra effort of indexing.

W3Schools

w3schools.com › python › python_strings.asp

Python Strings

Get the character at position 1 (remember that the first character has the position 0): a = "Hello, World!" print(a[1]) Try it Yourself » · Since strings are arrays, we can loop through the characters in a string, with a for loop.

Quora

quora.com › How-can-we-use-for-loop-to-iterate-through-each-character-of-a-string

How can we use for loop to iterate through each character of a string? - Quora

Answer (1 of 2): The details vary, depending on the language. In Python, I would simply: [code]for character in my_string: print(character) [/code]Otherwise, if your programming language doesn’t allow this sort of construct, you can make a loop that changes a variable, from 1 to len(string),...

reddit.com › r/learnprogramming › using while loops to find a character in a string

r/learnprogramming on Reddit: Using while loops to find a character in a string

December 20, 2022 -

I want to use the while loop to return the position of a character in a string.

I found this solution:

x = "abcdefg"
while "e" in x:
      print("the character e has been found at position", x.index("e"))
      break

I did the same thing with a for loop. Ignore the bad sintax please.

count =0 
for i in "abcdefg...."
  if i=="j":
    print(count)
break
  else:
       count=count+1
print(count)

Ok, so... I would like to have an alternative solution with while, that has a similar logic to this last one.

Top answer

1 of 2

1

s = "abcdef" currIndex = 0 length = len(s) while currIndex < length: if s[currIndex] == 'e': print(currIndex) currIndex += 1 create an index variable (currIndex) set to the starting point of the string, 0. create a limit variable for your index (length), in this case the limit is the length of the string. set your while loop to execute as long as currIndex is less than the limit. keep in mind the length of the string will always be one higher than the last index..hense "<" instead of "<=". the first character is at index 0, and the last is at len(s)-1. each iteration of the while loop checks if the character of s at currIndex is equal to the char you're looking for and prints currIndex if it is. increment currIndex by 1

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This absolutely does not do what you want it to do. x = "abcdefg" while "e" in x: print("the character e has been found at position", x.index("e")) break A while loop that always breaks is just an if. This code is: if "e" in x: print("the character e has been found at position", x.index("e")) You could just use the index function directly and avoid all the faff. For the while loop you could do something like (pseudo-code following): while index < length of string if string[index] == "e" break count = count + 1 print count The Python foreach loop is cleaner. Or just use index(). That's what it's there for.

Devcamp

bottega.devcamp.com › full-stack-development-javascript-python › guide › how-to-loop-through-characters-python-string

How to Loop Through the Characters of a Python String

This is going to be a quick guide ... in python and we see that the for in loop can also be used with strings. ... So if I have a string that contains a portion of the alphabet. I could say alphabet and inside of that put abcdef. ... and if I want to loop through each one of those items a 4 in the loop allows me to access them just like they were in a collection because if you think about it a string is really just a collection of characters so it's almost ...

TutorialsPoint

tutorialspoint.com › iterate-over-characters-of-a-string-in-python

Iterate over characters of a string in Python

July 1, 2020 - text = "tutorialspoint" # Iterate over the string for char in text: print(char, end='')

Stack Overflow

stackoverflow.com › questions › 45923230 › how-to-loop-through-a-string-and-return-a-new-string-that-stops-at-a-specific-ch › 45923297

python - How to Loop through a string and return a new string that stops at a specific character - Stack Overflow

Top answer

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If you just want to get the substring from the beginning of the long string until a certain char, you can just do the following:

>>> ch = 'r'
>>> s = 'Hello, world!'
>>> print(s[:s.find(ch)])
#  Hello, wo

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1

try:
    print d[:d.index('y')]
except ValueError:
    print d

Stanford

web.stanford.edu › class › archive › cs › cs106a › cs106a.1214 › templates › handouts_w2021 › lecture-12.html

examples of features below: "foreach" and "in"

intersect(a, b): Given two strings, a and b. Return a version of a, including only those chars which also appear in b. Use a case-sensitive comparison. Use a for/ch/s loop. ... def intersect(a, b): result = '' # Look at all chars in a, check # each using "in" for ch in a: if ch in b: result += ch return result · See the guide: Python List for more details about lists