I'm very new to regex and I need to read in from a text file and find a word after a particular word + characters. For example, the content of the text file is:
Weather now : Mildly-sunny34 Weather tomorrow : Cloudy
I want to extract "Mildly-sunny34" after searching for the keyword "Weather now" from the text doc. I want to make sure I do not also get ":" or " " spaces apart from the word "Mildly-sunny34".
Any help with some explanation is much appreciated. Thanks!
This will do it:
import re
# Open the file for reading
with open('file.txt') as fd:
# Iterate over the lines
for line in fd:
# Capture one-or-more characters of non-whitespace after the initial match
match = re.search(r'Weather now : (\S+)', line)
# Did we find a match?
if match:
# Yes, process it
weather = match.group(1)
print('weather: {}'.format(weather))
Since what you're capturing is non-whitespace that is delimited by whitespace, you can just use \S+.
\S is non-whitespace--the opposite of \s, which is whitespace+ indicates one or more of the previous character or character classFor the capture groups, group 0 corresponds to the entire regex and the captured subgroups are indexed sequentially. Since we only have one subgroup, we want group 1.
Running the above:
$ python extract.py
weather: Mildly-sunny34
