Kind of a noob here, apologies if I misstep.
I'm learning regular expressions and am on this lesson: https://regexone.com/lesson/capturing_groups.
In the python interpreter, I try to use the parentheses to only capture what precedes the .pdf part of the search string but my result captures it despite using the parens. What am I doing wrong?
import re
string_one = 'file_record_transcript.pdf'
string_two = 'file_07241999.pdf'
string_three = 'testfile_fake.pdf.tmp'
pattern = '^(file.+)\.pdf$'
a = re.search(pattern, string_one)
b = re.search(pattern, string_two)
c = re.search(pattern, string_three)
print(a.group() if a is not None else 'Not found')
print(b.group() if b is not None else 'Not found')
print(c.group() if c is not None else 'Not found')
Returns
file_record_transcript.pdf
file_07241999.pdf
Not found
But should return
file_record_transcript
file_07241999
Not found
Thanks!
You need the first captured group:
a.group(1)
b.group(1)
...
without any captured group specification as argument to group(), it will show the full match, like what you're getting now.
Here's an example:
In [8]: string_one = 'file_record_transcript.pdf'
In [9]: re.search(r'^(file.*)\.pdf$', string_one).group()
Out[9]: 'file_record_transcript.pdf'
In [10]: re.search(r'^(file.*)\.pdf$', string_one).group(1)
Out[10]: 'file_record_transcript'