regex – Python string.replace regular expression

regex – Python string.replace regular expression

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

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

regex – Python string.replace regular expression

As a summary

import sys
import re

f = sys.argv[1]
find = sys.argv[2]
replace = sys.argv[3]
with open (f, r) as myfile:
     s=myfile.read()
ret = re.sub(find,replace, s)   # <<< This is where the magic happens
print ret