概要

Pythonで「マッチオブジェクトからマッチした文字列の情報を取得する(Match)」の動作を確認してみました。
以下のページを参考にしました。

実装

以下のファイルを作成しました。

sample.py

import re

msg = 'My birthday is 1998/09/25'
pattern = re.compile(r'\d{4}/\d{2}/\d{2}')

result = pattern.search(msg)
if result :
    print('Match:' + result.group(0))

import re

msg = 'My birthday is 1998/09/25'
pattern = re.compile(r'(\d{4})/(\d{2})/(\d{2})')

result = pattern.search(msg)
if result :
    print('Match:' + result.group(0))
    print('Group1:' + result.group(1))
    print('Group2:' + result.group(2))
    print('Group3:' + result.group(3))

import re

msg = 'My birthday is 1998/09/25'
pattern = re.compile(r'(?P<year>\d{4})/(?P<month>\d{2})/(?P<day>\d{2})')

result = pattern.search(msg)
if result :
    print('Match:' + result.group(0))
    print('Group[year]:' + result.group('year'))
    print('Group[month]:' + result.group('month'))
    print('Group[day]:' + result.group('day'))

import re

msg = 'My birthday is 1998/09/25'
pattern = re.compile(r'(\d{4})/(\d{2})/(\d{2})')

result = pattern.search(msg)
if result :
    print(result.group(1, 2, 3))

import re

msg = 'My birthday is 1998/09/25'
pattern = re.compile(r'\d{4}/\d{2}/\d{2}')

result = pattern.search(msg)
if result :
    print('Match:' + result.group(0))
    print('StartIndex:' + str(result.start(0)))
    print('EndIndex:' + str(result.end(0)))

import re

msg = 'My birthday is 1998/09/25'
pattern = re.compile(r'(\d{4})/(\d{2})/(\d{2})')

result = pattern.search(msg)
if result :
    print('Group1:' + result.group(1))
    print('StartIndex:' + str(result.start(1)))
    print('EndIndex:' + str(result.end(1)))

import re

msg = 'My birthday is 1998/09/25'
pattern = re.compile(r'(\d{4})/(\d{2})/(\d{2})')

result = pattern.search(msg)
if result :
    for i in range(result.lastindex):
      print('Group:' + str(i + 1) + ' ' + result.group(i + 1))

以下のコマンドを実行しました。

$ python3 sample.py 
Match:1998/09/25
Match:1998/09/25
Group1:1998
Group2:09
Group3:25
Match:1998/09/25
Group[year]:1998
Group[month]:09
Group[day]:25
('1998', '09', '25')
Match:1998/09/25
StartIndex:15
EndIndex:25
Group1:1998
StartIndex:15
EndIndex:19
Group:1 1998
Group:2 09
Group:3 25

まとめ

何かの役に立てばと。