CODEWITHSUNDEEP
pythonregex
Jeff F
Jeff F

Reputation: 1015

python regex for extracting number in string

My string is this:

<tr id="xyz21" style="" class="standard">

When I run my regex through the online regex helper site, pythex.org, I get what I'm wanting; only the number "21". The site says:

Match captures "21"

Here's the regex I used:

<tr id="xyz(.*?)"

However, when I use this same regex in my Python 3 script, I get much more. Here's the script with the result:

>>> import re
>>> x = '<tr id="xyz21" style="" class="standard">'
>>> num = re.search('<tr id="xyz(.*?)"', x).group()
>>> print(num)
<tr id="xyz21"

Ultimately, all I want is to create a variable with a value of "21". By the way, the actual string I use the regex on is a lot longer than what I'm showing. It's a small file, actually. I've simplified my example just to make it easier to understand. Any ideas?

Upvotes: 0

Views: 110

Answers (1)

zw324
zw324

Reputation: 27180

You need to add a parameter:

re.search('<tr id="xyz(.*?)"', x).group(1)

The documentation noted that

If there is a single argument, the result is a single string; if there are multiple arguments, the result is a tuple with one item per argument. Without arguments, group1 defaults to zero (the whole match is returned). If a groupN argument is zero, the corresponding return value is the entire matching string; if it is in the inclusive range [1..99], it is the string matching the corresponding parenthesized group.

Upvotes: 1

Related Questions