CODEWITHSUNDEEP
pythonregex
Alex Bruce
Alex Bruce

Reputation: 553

python regex to find the substring from the string

I have a string:

 <robot generated="20170330 17:19:11.956" generator="Robot 3.0.2 (Python 2.7.13 on win32)">

I want to get the value of "generated", but with below code, it doesn't work

import re
doc=r'<robot generated="20170330 17:19:11.956" generator="Robot 3.0.2 (Python 2.7.13 on win32)">'
match = re.match(r'generated="(\d+ \d+:\d+:\d+.\d+)',doc)

the value of match is none. can anyone help?

Upvotes: 2

Views: 412

Answers (2)

falsetru
falsetru

Reputation: 369424

re.match matches only at the beginning of the string. Use re.search instead which matches not only at the beginning, but matches anywhere.

>>> import re
>>> doc=r'<robot generated="20170330 17:19:11.956" generator="Robot 3.0.2 (Python 2.7.13 on win32)">'
>>> re.search(r'generated="(\d+ \d+:\d+:\d+\.\d+)',doc)
<_sre.SRE_Match object at 0x1010505d0>

>>> re.search(r'generated="(\d+ \d+:\d+:\d+\.\d+)',doc).group()
'generated="20170330 17:19:11.956'

>>> re.search(r'generated="(\d+ \d+:\d+:\d+\.\d+)',doc).group(1)
'20170330 17:19:11.956'

See search() vs. match() from re module documentation

Upvotes: 2

alecxe
alecxe

Reputation: 474161

You don't necessarily need regular expressions in this case. Here is an alternative idea that uses BeautifulSoup XML/HTML parser with dateutil datetime parser:

In [1]: from dateutil.parser import parse

In [2]: from bs4 import BeautifulSoup

In [3]: data = '<robot generated="20170330 17:19:11.956" generator="Robot 3.0.2 (Python 2.7.13 on win32)">'

In [4]: parse(BeautifulSoup(data, "html.parser").robot['generated'])
Out[4]: datetime.datetime(2017, 3, 30, 17, 19, 11, 956000)

I find this approach beautiful, easy and straightforward.

Upvotes: 1

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