Python get N characters from string with specific substring-CodePudding

I have a very long string that I extracted from a image file. The string can look like this

...\n\nDate: 01.01.2022\n\nArticle-no: 123456789\n\nArticle description: asdfqwer 1234...\n...

How do I extract just the 10 characters after the substring "Article-no:"?

I tried solving it with a different approach using rfind like this but it tends to fail every now and then if the start and end string is not accurate.

    s = "... string shown above ..."
    start = "Article-no: "
    end = "Article description: "
    print(s[s.find(start) len(start):s.rfind(end)])

CodePudding user response：

you can use split:

string.split("Article-no: ", 1)[1][0:10]

CodePudding user response：

For this, a regular expression might come in very handy.

import re

# Create a pattern which matches "Article-no: " literally,
# and then grabs the digits that follow.
pattern = re.compile(r"Article-no: (\d )")
s = "...\n\nDate: 01.01.2022\n\nArticle-no: 123456789\n\nArticle description: asdfqwer 1234...\n..."

match = pattern.search(s)
if match:
    print(match.group(1))

This outputs:

123456789

The regular expression used is Article-no: (\d ), which has the following parts:

Article-no:      # Match this text literally
(                # Open a new group (i.e. group 1)
\d               # Match 1 or more occurrences of a digit
)                # Close group 1

The re module will search the string for places where this matches, and then you can extract the digit from the matches.