No. Regular expressions in Python are handled by the re module.
article = re.sub(r'(?is)</html>.+', '</html>', article)
In general:
str_output = re.sub(regex_search_term, regex_replacement, str_input)
No. Regular expressions in Python are handled by the re module.
article = re.sub(r'(?is)</html>.+', '</html>', article)
In general:
str_output = re.sub(regex_search_term, regex_replacement, str_input)
In order to replace text using regular expression use the re.sub function:
sub(pattern, repl, string[, count, flags])
It will replace non-everlaping instances of pattern by the text passed as string. If you need to analyze the match to extract information about specific group captures, for instance, you can pass a function to the string argument. more info here.
Examples
>>> import re
>>> re.sub(r'a', 'b', 'banana')
'bbnbnb'
>>> re.sub(r'/\d+', '/{id}', '/andre/23/abobora/43435')
'/andre/{id}/abobora/{id}'
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
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!
str.replace() does fixed replacements. Use re.sub() instead.
Hi,
The title may not be perfect but I could not think of a better one.
How am I able to do a regex search within a string and replace all occurrences with a modified version of the matching part?
Background:
The task I'm going to do is that I'm looking for regex for ISO datestamps and shift them according to a user-defined delta in days. Therefore, I'm looking for r'(?P<year>\d{4,4})-(?P<month>[01]\d)-(?P<day>[0123]\d)'. When I've got matches, I want to retrieve each match, add or subtract a delta in days to it and replace its original date-stamp accordingly.
I got the impression that re.subn() is not able to do something like this for me:
re.subn(r'(?P<year>\d{4,4})-(?P<month>[01]\d)-(?P<day>[0123]\d)', calculate_shifted_ISO_string_from_ymd(\1, \2, \3), line_to_parse)
Is my only option to separate the identification of matches, manually split the string for each occurrence, generate a datetime from the extracted string, add a delta-datetime in days and re-concatenate the result for all occurrences?
SOLUTION:
I chose the provided tip to use a function as described in the comments below.
The resulting tool which shifts ISO date-stamps within text-files is hosted on https://github.com/novoid/isodateshifter