regex to extract postal code from an address

Question

I have a list of addresses have merged postal codes shown below

65 Windermere Ave., Toronto, ON, M6S 3J4
15 Bruyeres Mews, Toronto, ON M5V 0G8, Canada
M6M1N7, Canada
437 revus Ave, L5G 1S2, Mississauga, ON
, ST. CATHARINES L2M 6Z2 ON
15 Viking Lane, Toronto M9B0A4 ON

I tried this regex to extract postal code but got no output

^.{3}(?:[\s]).{3}^$

Update

postal codes examples: M6S 3J4,L5G 1S2,M9B0A4

Would [this](https://stackoverflow.com/a/46761018/9758194) be helpfull? — JvdV, Jan 20 '21 at 07:07

Leo Arad · Accepted Answer · 2021-01-20T07:10:36.693

4

You can try this regex (([A-Z]\d[A-Z])+\s?\d[A-Z]\d) that will find all the upper case letter follows by digit and other upper case letter and then it checks if there is a space followed by digit upper case letter and another digit.

import re

txt = """
65 Windermere Ave., Toronto, ON, M6S 3J4
15 Bruyeres Mews, Toronto, ON M5V 0G8, Canada
M6M1N7, Canada
437 revus Ave, L5G 1S2, Mississauga, ON
, ST. CATHARINES L2M 6Z2 ON
15 Viking Lane, Toronto M9B0A4 ON
"""

print([i[0] for i in re.findall(r"(([A-Z]{1}\d{1}[A-Z]{1})+\s?(\d{1}[A-Z]{1}\d{1})*)", txt)])

Output

['M6S 3J4', 'M5V 0G8', 'M6M1N7', 'L5G 1S2', 'L2M 6Z2', 'M9B0A4']

edited Jan 20 '21 at 07:10

answered Jan 20 '21 at 06:54

Leo Arad

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1

`{1}` is unnecessary – anubhava Jan 20 '21 at 07:09
1

@anubhava Thanks I removed the `{1}` from the regex. – Leo Arad Jan 20 '21 at 07:11

costaparas · Answer 2 · 2021-01-20T07:01:12.833

Canadian postal codes take the format A1A 1A1 where A is a letter and 1 is a digit. You're better off matching that explicitly in your regex.

A working regex would look like this:

[A-Z]\d[A-Z]\s?\d[A-Z]\d

A few things to note:

Your current regex is anchoring the match which you don't want to do in this case
You will want to use re.search and not re.match, since re.match anchors the match
Make the \s optional using ? (which means zero or one occurrences)

Here's a working example:

lines = '''65 Windermere Ave., Toronto, ON, M6S 3J4
15 Bruyeres Mews, Toronto, ON M5V 0G8, Canada
M6M1N7, Canada
437 revus Ave, L5G 1S2, Mississauga, ON
, ST. CATHARINES L2M 6Z2 ON
15 Viking Lane, Toronto M9B0A4 ON'''

import re

for s in lines.split('\n'):
    m = re.search(r'([A-Z]\d[A-Z]\s?\d[A-Z]\d)', s)
    if m:
        print(m.group(1))

Output:

M6S 3J4
M5V 0G8
M6M1N7
L5G 1S2
L2M 6Z2
M9B0A4

If you want a fully general solution for matching postal codes from around the world, then check out this post.

regex to extract postal code from an address

2 Answers2