Python match regex always returning None

Question

I have a python regex that match method always return None. I tested in pythex site and the pattern seems OK. Pythex example But when I try with re module, the result is always None: ``` import re a = re.match(re.compile("\.aspx\?.*cp="), 'page.aspx?cpm=549&cp=168') ``` What am I doing wrong?

Accepted Answer

`re.match()` only matches at the start of a string. Use `re.search()` instead:

```
re.search(r"\.aspx\?.*cp=", 'page.aspx?cpm=549&cp=168')
```

Demo:

```
>>> import re
>>> re.search(r"\.aspx\?.*cp=", 'page.aspx?cpm=549&cp=168')
<_sre.SRE_Match object at 0x105d7e440>
>>> re.search(r"\.aspx\?.*cp=", 'page.aspx?cpm=549&cp=168').group(0)
'.aspx?cpm=549&cp='
```

Note that any `re` functions that take a pattern, accept a string and will call `re.compile()` for you (which caches compilation results). You only need to use `re.compile()` if you want to store the compiled expression for re-use, at which point you can call `pattern.search()` on it:

```
pattern = re.compile(r"\.aspx\?.*cp=")
pattern.search('page.aspx?cpm=549&cp=168')
```

Python match regex always returning None

Solution

Problem