Multiple re.sub() statements

Question

In my program, the user enters a term which I process before sending on. Part of this process is to change all instances of 'and','or' and 'not' to uppercase letters but leaving the rest intact. I can't use `string.upper()` because it changes everything to uppercase; or `string.replace()` because if 'and' is in another word in the string e.g. 'salamander' it will also change that to 'salamANDer'. I think my best option is the regex `re.sub()` function. This allows me to change full words which is perfect. Next problem: I have to do a `re.sub()` function for each change I want to make. Is it possible to make one statement to do all the changes? What I have done isn't wrong but I don't think its necessarily good practice: ``` >>import urllib2 >>import re >>query = 'Lizards and Amphibians not salamander or newt' >>query=re.sub(r'\bnot\b', 'NOT',query) >>query=re.sub(r'\bor\b', 'OR',query) >>query=re.sub(r'\band\b', 'AND',query) >>query = urllib2.quote("'"+query+"'") >>print query %27Liza…

Accepted Answer

You can pass a function substitution expression in `re.sub()`:

```
>>> term = "Lizards and Amphibians not salamander or newt"
>>> re.sub(r"\b(not|or|and)\b", lambda m: m.group().upper(), term)
'Lizards AND Amphibians NOT salamander OR newt'
```

However, I'd probably go with a non-regex solution:

```
>>> " ".join(s.upper() if s.lower() in ["and", "or", "not"] else s
...          for s in term.split())
'Lizards AND Amphibians NOT salamander OR newt'
```

This also normalizes the whitespace and works with mixed-case words like `And`.

Multiple re.sub() statements

Solution

Problem