python .replace() regex [duplicate] Ask Question Asked 12 years, 9 months ago. Modified 2 years, 3 months ago.

I want to replace one parameter's parameter-value with a new value. I am using a line replace function posted previously to replace the line which uses Python's string.replace(pattern, sub). The regular expression that I'm using works for instance in vim but doesn't appear to work in string.replace(). Here is the regular expression that I'm using:

If you can, try to tokenize data in this situation (break it into smaller parts based on regex rules) beforehand and replace based on these as this is more likely to be easier to accomplish the type of thing you are doing rather than dealing with the entire text document each time you are doing a replace, for example if you could just tokenize the <start> and <end> into separate things to ...

@Amber: I infer from your answer that unlike str.replace(), we can't use variables a) in raw strings; or b) as an argument to re.sub; or c) both. a) makes sense (I think) but I'm not sure about b). It seems we can use a variable name for the string the regex is going through, though. Would you care to elucidate? Thanks. –

Oct 12, 2016 · To further add to the above, the code below shows you how to replace multiple words at once! I've used this to replace 165,000 words in 1 step!! Note \b means no sub string matching..must be a whole word..if you remove it then it will make sub-string match. import re s = 'thisis a test' re.sub('\bthis\b|test','',s) This gives: 'thisis a '

Python Regex String Replace. 1. Python regex replace string. 1. Python regular expression replace string ...

A backreference to the whole match value is \g<0>, see re.sub documentation:. The backreference \g<0> substitutes in the entire substring matched by the RE.

This is Python's regex substitution (replace) function. The replacement string can be filled with so-called backreferences (backslash, group number) which are replaced with what was matched by the groups. Groups are counted the same as by the group(...) function, i.e. starting from 1, from left to right, by opening parentheses.

Feb 6, 2021 · How can I replace strings in a file with using regular expressions in Python? I want to open a file in which I should replace strings for other strings and we need to use regular expressions (search and replace).

Jun 29, 2011 · If you want it to work regardless of the character order, you need to put the regex in square brackets: re.sub(r"[\r\n]+", " ", html). Otherwise the regex in above answer is just as good as a normal string replace and not really using the additional functionality of regex. –