str.replace() v2|v3 does not recognize regular expressions.
To perform a substitution using a regular expression, use re.sub() v2|v3.
For example:
import re
line = re.sub(
r"(?i)^.*interfaceOpDataFile.*$",
"interfaceOpDataFile %s" % fileIn,
line
)
In a loop, it would be better to compile the regular expression first:
import re
regex = re.compile(r"^.*interfaceOpDataFile.*$", re.IGNORECASE)
for line in some_file:
line = regex.sub("interfaceOpDataFile %s" % fileIn, line)
# do something with the updated line
Top answer 1 of 4
750
str.replace() v2|v3 does not recognize regular expressions.
To perform a substitution using a regular expression, use re.sub() v2|v3.
For example:
import re
line = re.sub(
r"(?i)^.*interfaceOpDataFile.*$",
"interfaceOpDataFile %s" % fileIn,
line
)
In a loop, it would be better to compile the regular expression first:
import re
regex = re.compile(r"^.*interfaceOpDataFile.*$", re.IGNORECASE)
for line in some_file:
line = regex.sub("interfaceOpDataFile %s" % fileIn, line)
# do something with the updated line
2 of 4
529
You are looking for the re.sub function.
import re
s = "Example String"
replaced = re.sub('[ES]', 'a', s)
print(replaced)
will print axample atring
Python documentation
docs.python.org › 3 › library › re.html
re — Regular expression operations
May 25, 2026 - Source code: Lib/re/ This module provides regular expression matching operations similar to those found in Perl. Both patterns and strings to be searched can be Unicode strings ( str) as well as 8-...
python - How to input a regex in string.replace? - Stack Overflow
I need some help on declaring a regex. My inputs are like the following: this is a paragraph with in between and then there are cases ... where the number ranges fro... More on stackoverflow.com
Str.replace not working?
You probably just want this: updated['twitter_handle'] = updated['twitter_handle'].replace('?langen', '') More on reddit.com
7
1
January 20, 2021How do I incorporate in regular expressions ?
You can stick it in a string with hex escape codes. 160 would be '\xa0', if I can do math this late at night. See if your regex engine works if you just stick some of those in the literal. More on reddit.com
13
10
June 18, 2014How do you replace a character in a string with a single backslash?
r/learnpython is probably a better subreddit for these kinds of questions.
Having said that, your first example actually works, try:
print("apple".replace('l', '\\')) More on reddit.com 7
0
March 16, 2015Videos
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Note.nkmk.me
note.nkmk.me › home › python
Replace Strings in Python: replace(), translate(), and Regex
May 4, 2025 - Use the | operator to match multiple patterns. Each pattern may include special regex characters or literal substrings. This allows you to replace different substrings with the same string.
Top answer 1 of 7
881
This tested snippet should do it:
import re
line = re.sub(r"</?\[\d+>", "", line)
Edit: Here's a commented version explaining how it works:
line = re.sub(r"""
(?x) # Use free-spacing mode.
< # Match a literal '<'
/? # Optionally match a '/'
\[ # Match a literal '['
\d+ # Match one or more digits
> # Match a literal '>'
""", "", line)
Regexes are fun! But I would strongly recommend spending an hour or two studying the basics. For starters, you need to learn which characters are special: "metacharacters" which need to be escaped (i.e. with a backslash placed in front - and the rules are different inside and outside character classes.) There is an excellent online tutorial at: www.regular-expressions.info. The time you spend there will pay for itself many times over. Happy regexing!
2 of 7
66
str.replace() does fixed replacements. Use re.sub() instead.
W3Schools
w3schools.com › python › python_regex.asp
Python RegEx
RegEx can be used to check if a string contains the specified search pattern. Python has a built-in package called re, which can be used to work with Regular Expressions.
Pandas
pandas.pydata.org › docs › reference › api › pandas.Series.str.replace.html
pandas.Series.str.replace — pandas 3.0.4 documentation
Method to replace occurrences of a substring with another substring. ... Extract substrings using a regular expression. ... Find all occurrences of a pattern or regex in each string.
GeeksforGeeks
geeksforgeeks.org › python › python-substituting-patterns-in-text-using-regex
Python - Substituting patterns in text using regex - GeeksforGeeks
July 12, 2025 - # Python implementation of substituting a # specific text pattern in a string using regex # importing regex module import re # Function to perform # operations on the strings def substitutor(): # a string variable sentence1 = "It is raining outside." # replacing text 'raining' in the string # variable sentence1 with 'sunny' thus # passing first parameter as raining # second as sunny, third as the # variable name in which string is stored # and printing the modified string print(re.sub(r"raining", "sunny", sentence1)) # a string variable sentence2 = "Thank you very very much."
Plain English
python.plainenglish.io › the-incredible-power-of-pythons-replace-regex-6cc217643f37
The incredible power of Python’s replace regex | by Josh Weinstein | Python in Plain English
November 1, 2020 - In the first argument to the re.sub ... in the regex, of three, three, and four digits long, respectively. This pattern is designed to match 10 digit phone numbers which have no format that’s usually used in contact information or distinguishes the area code. The second argument, the replace string, is a template string which specifies the interpolation of the captured groups. In Python’s regex, ...
Flexiple
flexiple.com › python › python-regex-replace
Python regex: How to search and replace strings | Flexiple - Flexiple
To replace a string in Python, the regex sub() method is used. It is a built-in Python method in the re module that returns a replaced string. Don't forget to import the re module.
W3Schools
w3schools.com › python › ref_string_replace.asp
Python String replace() Method
Remove List Duplicates Reverse ... Interview Q&A Python Bootcamp Python Training ... The replace() method replaces a specified phrase with another specified phrase....
PYnative
pynative.com › home › python › regex › python regex replace pattern in a string using re.sub()
Python Regex Replace Pattern in a string using re.sub()
July 19, 2021 - import re # replacement function to convert uppercase letter to lowercase def convert_to_lower(match_obj): if match_obj.group() is not None: return match_obj.group().lower() # Original String str = "Emma LOves PINEAPPLE DEssert and COCONUT Ice Cream" # pass replacement function to re.sub() res_str = re.sub(r"[A-Z]", convert_to_lower, str) # String after replacement print(res_str) # Output 'Emma loves pineapple dessert and coconut Ice Cream'Code language: Python (python) Run · We saw how to find and replace the single regex pattern in the earlier examples.
PythonTest
pythontest.com › python › regex-search-replace
Python regex Search and Replace Examples | PythonTest
I think the most basic form of a search/replace script in python is something like this: import fileinput import re for line in fileinput.input(): line = re.sub('foo','bar', line.rstrip()) print(line) The fileinput module takes care of the stream verses filename input handling. The re (regex, regular expression) module has sub which handles the search/replace.
TechGeekBuzz
techgeekbuzz.com › blog › python-regex-replace-pattern-in-a-string-using-re-sub
Python Regex Replace Pattern in a string using re.sub()
To do this, we learned two regex methods sub() and subn() . The sub() method accept a regular expression pattern, and replace all the matched pattern of the string with the replacement string or function, and return the newly replaced string.
GeeksforGeeks
geeksforgeeks.org › python › python-regex-replace-captured-groups
Python Regex: Replace Captured Groups - GeeksforGeeks
July 23, 2025 - `string`: The original string where the replacement is performed. `count`: The maximum number of replacements. Default is `0`, which means replace all occurrences. `flags`: Optional flags to modify the regex behavior. Python provides several ways to replace captured groups in a string:
Real Python
realpython.com › replace-string-python
How to Replace a String in Python – Real Python
January 15, 2025 - In this tutorial, you'll learn how to remove or replace a string or substring. You'll go from the basic string method .replace() all the way up to a multi-layer regex pattern using the sub() function from Python's re module.
Index.dev
index.dev › blog › regex-advanced-string-replacement-python
Python Regex Replace: How to Replace Strings Using re Module
The re.sub() function is the primary tool for performing string replacements with regex in Python. It allows you to specify a regex pattern to search for, a replacement string, and the target string where the replacement will occur.
Table Convert
tableconvert.com › home › table convert
Table Convert - Free Online Table Converter and Generator
July 28, 2025 - Edit data using our advanced online table editor with professional features. Supports deleting empty rows, removing duplicates, data transposition, sorting, regex find & replace, and real-time preview.
RegExr
regexr.com
RegExr: Learn, Build, & Test RegEx
Full RegEx Reference with help & examples.
freeCodeCamp
freecodecamp.org › news › javascript-string-replace-example-with-regex
JavaScript String.Replace() Example with RegEx
October 20, 2020 - With RegEx, you can match strings at points that match specific characters (for example, JavaScript) or patterns (for example, NumberStringSymbol - 3a&). The .replace method is used on strings in JavaScript to replace parts of string with characters.
Leapcell
leapcell.io › blog › how-to-use-python-regex-for-string-replacement
How to Use Python Regex for String Replacement | Leapcell
July 25, 2025 - To use regex in Python, first import the built-in re module: ... The main function used for regex replacement is re.sub(pattern, repl, string).