Different behavior between re.finditer and re.findall

re.findall(pattern.string)

findall() returns all non-overlapping matches of pattern in string as a list of strings.

re.finditer()

finditer() returns callable object.

In both functions, the string is scanned from left to right and matches are returned in order found.


I can't reproduce this here. Have tried it with both Python 2.7 and 3.1.

One difference between finditer and findall is that the former returns regex match objects whereas the other returns a tuple of the matched capturing groups (or the entire match if there are no capturing groups).

So

import re
CARRIS_REGEX=r'<th>(\d+)</th><th>([\s\w\.\-]+)</th><th>(\d+:\d+)</th><th>(\d+m)</th>'
pattern = re.compile(CARRIS_REGEX, re.UNICODE)
mailbody = open("test.txt").read()
for match in pattern.finditer(mailbody):
    print(match)
print()
for match in pattern.findall(mailbody):
    print(match)

prints

<_sre.SRE_Match object at 0x00A63758>
<_sre.SRE_Match object at 0x00A63F98>
<_sre.SRE_Match object at 0x00A63758>
<_sre.SRE_Match object at 0x00A63F98>
<_sre.SRE_Match object at 0x00A63758>
<_sre.SRE_Match object at 0x00A63F98>
<_sre.SRE_Match object at 0x00A63758>
<_sre.SRE_Match object at 0x00A63F98>

('790', 'PR. REAL', '21:06', '04m')
('758', 'PORTAS BENFICA', '21:10', '09m')
('790', 'PR. REAL', '21:14', '13m')
('758', 'PORTAS BENFICA', '21:21', '19m')
('790', 'PR. REAL', '21:29', '28m')
('758', 'PORTAS BENFICA', '21:38', '36m')
('758', 'SETE RIOS', '21:49', '47m')
('758', 'SETE RIOS', '22:09', '68m')

If you want the same output from finditer as you're getting from findall, you need

for match in pattern.finditer(mailbody):
    print(tuple(match.groups()))

Tags:

Python

Regex