如何从字符串中提取第一组整数？

Question

I need to extract the numbers beside # from the string: ackCount. I am using indexing, but the number of digits beside hash may increase to 5 or 6..so on. Can I get only the number immediately after the # (Not 1 that is at the last of the string) Below is the temporary code for getting 4 digits

ackCount = "Acknowledgement of  #2352 on component \"lOrA-1\""
OAC = int(re.sub("\\D", "", ackCount)[0:4])
print(OAC)

Answer 1

re.search(r"#(\d+)", ackCount).group(1)

This will search the ackCount string for the first occurrence of a an octothorpe ('#') followed by one or more ( + ) digits ( \d ), capturing only the digit(s) in the capture group ( .group(1) ) of the Match object returned by re.search() .

In the context of your question, this would become:

ackCount = "Acknowledgement of  #2352 on component \"lOrA-1\""
try:
    OAC = int(re.search(r"#(\d+)", ackCount).group(1))
    print(OAC)
# error handling if the cast to `int` fails, or there is no returned match
except ValueError, AttributeError:
    print("No match found.")

>>> 2352

Answer 2

If the string is always the same you can use ackCount = ackCount.split()

This will return you a list where each element is a word in your original string. By default split() uses blank spaces as the delimiter.

Then get all the digits with ackCount[2][1:] , again assuming it is the same general string but just the digits are different. So index 2 of your list, and then all characters of the string beginning at index 1 (because index 0 of the string is '#').

Answer 3

You can use regex for this purpose. Make sure you make the right pattern: The following will return a list of all matches:

import re
string = "he hallo #9090 8080 fdsf sfd222 f222"
find = re.findall("(?<=#)[0-9]+\\b", string)
print(find)

Output: ['9090']

The string string = "he hallo #9090 8080 fdsf sfd222 f222 #888" will return ['9090', '888'] etc.