username = 'MICHAEL89'
if username.upper() in (name.upper() for name in USERNAMES):
...
Alternatively:
if username.upper() in map(str.upper, USERNAMES):
...
Or, yes, you can make a custom method.
Answer from nmichaels on Stack Overflow Top answer 1 of 12
264
username = 'MICHAEL89'
if username.upper() in (name.upper() for name in USERNAMES):
...
Alternatively:
if username.upper() in map(str.upper, USERNAMES):
...
Or, yes, you can make a custom method.
2 of 12
61
str.casefold is recommended for case-insensitive string matching. @nmichaels's solution can trivially be adapted.
Use either:
if 'MICHAEL89'.casefold() in (name.casefold() for name in USERNAMES):
Or:
if 'MICHAEL89'.casefold() in map(str.casefold, USERNAMES):
As per the docs:
Casefolding is similar to lowercasing but more aggressive because it is intended to remove all case distinctions in a string. For example, the German lowercase letter 'ß' is equivalent to "ss". Since it is already lowercase,
lower()would do nothing to 'ß';casefold()converts it to "ss".
Top answer 1 of 10
232
If you don't want to use str.lower(), you can use a regular expression:
import re
if re.search('mandy', 'Mandy Pande', re.IGNORECASE):
# Is True
2 of 10
51
You are looking for the .lower() method:
string1 = "hi"
string2 = "HI"
if string1.lower() == string2.lower():
print("Equals!")
else:
print("Different!")
Btw, There's another post here. Try looking at this.
How to use Casefold Method for case insensitive string comparison ...
13:44
Python Tips and Tricks: Case-Insensitive String Comparisons Done ...
07:33
Case Insensitive Matching in Python with .Casefold() - YouTube
03:12
Case insensitive string.Contains in C# - YouTube
05:03
Check if a Value Exists in a List Using Python (Case Insensitive) ...
GeeksforGeeks
geeksforgeeks.org › python › case-insensitive-string-comparison-in-python
Case-insensitive string comparison in Python - GeeksforGeeks
July 15, 2025 - Explanation: This code uses casefold() for accurate case-insensitive comparison, especially with international characters. It converts all strings, checks uniqueness using a set and prints "equal" if all are identical otherwise, "unequal". re.match() checks if a string matches a pattern from the start and with the re.IGNORECASE flag, it ignores case differences.
Bobby Hadz
bobbyhadz.com › blog › python-check-if-string-is-in-list-case-insensitive
Check if List contains a String case-insensitive in Python | bobbyhadz
Use the in operator to check if the string is in the list in a case-insensitive manner.
EyeHunts
tutorial.eyehunts.com › home › python string contains case insensitive | example code
Python string contains case insensitive | Example code
April 25, 2022 - str1 = "Messi is the best SoCceR player" if "soccer" in str1.lower(): print("Contain soccer") if "Player" in str1: print("Contain football") ... Answer: Make the string lowercase or uppercase before matching it. ... Do comment if you have any doubts or suggestions on this Python string topic.
Mathspp
mathspp.com › blog › how-to-work-with-case-insensitive-strings
How to work with case-insensitive strings | mathspp
January 21, 2023 - To implement a case-insensitive dictionary in Python, we need to use the string method str.casefold whenever we are setting, getting, or deleting a key from the dictionary.
thisPointer
thispointer.com › home › python › python : check if a string contains a sub string & find it’s index | case insensitive
Python : Check if a String contains a sub string & find it's index | case insensitive - thisPointer
April 30, 2023 - As our main string doesn’t contains the sub-string ‘Hello’ therefore ‘not in’ operator returned True. Check if First Letter of String is Uppercase in Python ... Python : Find occurrence count & all indices of a sub-string in another string | including overlapping sub-strings · To check if a given string or a character exists in an another string or not in case insensitive manner i.e.
Top answer 1 of 5
40
if 'power' in choice.lower():
should do (assuming choice is a string). This will be true if choice contains the word power. If you want to check for equality, use == instead of in.
Also, if you want to make sure that you match power only as a whole word (and not as a part of horsepower or powerhouse), then use regular expressions:
import re
if re.search(r'\bpower\b', choice, re.I):
2 of 5
11
This if you're doing exact comparison.
if choice.lower() == "power":
Or this, if you're doing substring comparison.
if "power" in choice.lower():
You also have choice.lower().startswith( "power" ) if that interests you.
LearnPython.com
learnpython.com › blog › python-case-sensitive
Is Python Case-Sensitive? | LearnPython.com
Using the casefold() method is the strongest and the most aggressive approach to string comparison in Python. It’s similar to lower(), but it removes all case distinctions in strings. This is a more efficient way to make case-insensitive comparisons in Python.
Codecademy
codecademy.com › article › how-to-check-if-a-string-contains-a-substring-in-python
How to Check if a String Contains a Substring in Python | Codecademy
The built-in .lower() method in Python converts all the characters of a string to lowercase. This method is especially helpful for case-insensitive string comparisons and searches because it maintains consistency and avoids mismatches resulting from different capitalizations by ensuring all characters are lowercase.
TutorialsPoint
tutorialspoint.com › how-do-i-do-a-case-insensitive-string-comparison-in-python
How do I do a case-insensitive string comparison in Python?
June 10, 2025 - str1 = "Tutorialspoint" str2 = "TUTORIALSPOINT" if str1.upper() == str2.upper(): print("The strings are equal i.e., case-insensitive") else: print("The strings are not equal") ... The casefold() method in Python is similar to the lower() method, but the difference is caseless matching, which is useful for comparing strings containing special characters or Unicode.
Delft Stack
delftstack.com › home › howto › python › case insensitive string comparison in python
How to Compare String Case Insensitive String in Python | Delft Stack
February 2, 2024 - It returns a string with all the characters converted into lower case alphabets. We can convert two strings to the lower case with the lower() method and then compare them case-insensitively.
Metaschool
metaschool.so › home › software development › master string searches in python 2025
Master String Searches in Python 2025
February 7, 2025 - Yes, string containment checks in Python are case-sensitive by default. This means that the check will distinguish between uppercase and lowercase characters. For instance, checking if "hello" is in "Hello World" will return False because of ...
Top answer 1 of 2
111
Series.str.contains has a case parameter that is True by default. Set it to False to do a case insensitive match.
df2 = df1['company_name'].str.contains("apple", na=False, case=False)
2 of 2
3
If you want to do the exact match and with strip the search on both sides with case ignore,
df[df['Asset Name'].str.strip().str.match('searchstring'.strip(), case=False)]
GeeksforGeeks
geeksforgeeks.org › python › python-case-insensitive-string-replacement
Case insensitive string replacement in Python - GeeksforGeeks
July 23, 2025 - Explanation: re.sub(r"(?i)best", lambda m: "good", a) uses a case-insensitive regex ((?i) inline flag) to match the word "best" in any casing within the string a, and replaces each match using a lambda function that returns "good".
DataScientYst
datascientyst.com › pandas-contains-using-case-insensitive-search
Pandas: Contains Using Case Insensitive Search
May 16, 2025 - To perform case-insensitive string matching in Pandas, you can use the .str accessor along with regular expressions and the case=False parameter (1) parameter case of str.contains df1['col'].str.contains("MaX", na=False, case=False) (2) Margin ...
Reddit
reddit.com › r/learnpython › help with ignorecase
r/learnpython on Reddit: help with IGNORECASE
October 31, 2022 -
I have simple find loop but I want it to ignore case and I just cant get it to .
import re
names = ['Tilt back', 'speed', 'gist']
for name in names:
if name.startswith('tilt', re.IGNORECASE):
print(name) Top answer 1 of 2
3
https://docs.python.org/3/library/stdtypes.html#str.startswith startswith doesn't take an "ignore case" parameter because there are no circumstances under which it will ignore case.
2 of 2
3
If you want to ignore case with simple string methods, first convert everything to the same case. The string method casefold() is meant for this. https://docs.python.org/3/library/stdtypes.html#str.casefold You could also just use upper or lower as long as you are consistent, but they might not support certain Unicode or other languages. The flags in re only apply to the methods in re, like re.search or re.match
Python
python.org › dev › peps › pep-0235
PEP 235 -- Import on Case-Insensitive Platforms | Python.org
February 21, 2001 - Despite that the filesystem is case-insensitive, Python insists on a case-sensitive match.
LabEx
labex.io › tutorials › python-how-to-compare-two-python-strings-for-equality-in-a-case-insensitive-manner-395043
How to compare two Python strings for equality in a case-insensitive manner? | LabEx
- Whole word matches: 3 - All matches: 3 Scenario: No matches Text: 'No matches here' - Whole word matches: 0 - All matches: 0 Scenario: Mixed word boundaries Text: 'Python-script and PythonProgram contain python' - Whole word matches: 1 - All matches: 3 · This demonstrates how case-insensitive comparison can be used in a real-world search function, with options to handle different searching requirements.
Bytes
bytes.com › topic › python › answers › 598831-string-find-case-insensitive-search
string.find for case insensitive search - Python
November 1, 2015 - string.find for case insensitive search. Python Forums on Bytes.