Increment a Version Number using Regular Expression

Question

Hello,

I am trying to increment a version number using regex but I can't seem to get the hang of regex at all. I'm having trouple with the symbols in the string I am trying to read and change. The code I have so far is:

version_file = "AssemblyInfo.cs" 
read_file = open(version_file).readlines() 
write_file = open(version_file, "w") 
r = re.compile(r'(AssemblyFileVersion\s*(\s*"\s*)(\S+))\s*"\s*') 

for l in read_file: 
    m1 = r.match(l) 
    if m1: 
        VERSION_ID=map(int,m1.group(2).split(".")) 
        VERSION_ID[2]+=1 # increment version 
        l = r.sub(r'\g<1>' + '.'.join(['%s' % (v) for v in VERSION_ID]), l) 
    write_file.write(l) 
write_file.close()

The string I am trying to read and change is:

[assembly: AssemblyFileVersion("1.0.0.0")]

What I would like written to the file is:

[assembly: AssemblyFileVersion("1.0.0.1")]

So basically I want to increment the build number by one.

Can anyone help me fix my regualr expression. I seem to have trouble getting to grips with regular expression that have to get around symbols.

Thanks for any help.

Answer 1

If you specify the version as "1.0.0.*" then AFAIK it gets updated on each build automagically, at least if you're using Visual Studio.NET.

I'm not sure regex is your best bet, but one way of doing it would be this:

import re

# Don't bother matching everything, just the bits that matter.
pat = re.compile(r'AssemblyFileVersion.*\.(\d+)"')


# ... lines omitted which set up read_file, write_file etc.

for line in read_file:
    m = pat.search(line)
    if m:
        start, end = m.span(1)
        line = line[:start] + str(int(line[start:end]) + 1) + line[end:]
    write_file.write(line)

Answer 2

Good luck with regex.

If I had to do the same, I'd convert the string to int by removing the dots, add one and convert back to string.

Well, I'd have also used a integer version number in the first place.