You can adapt this ruby script, which calls git diff --stat in order to get those statistics.
For python, you have "git-loc"
2010-05-13 14:38:21 42 +44 -2 initial
2010-05-13 14:40:14 44 +3 -1 hashbang added
2010-05-13 14:40:14 49 +8 -3 show last commit too
Run it as `git-loc --svg' to output svg graph on stdout.
See git rev-parse SPECIFYING REVISIONS to check how to use dates:
<refname>@{<date>}, e.g. master@{yesterday}, HEAD@{5 minutes ago}
A ref followed by the suffix @ with a date specification enclosed in a brace pair (e.g. {yesterday}, {1 month 2 weeks 3 days 1 hour 1 second ago} or {1979-02-26 18:30:00}) specifies the value of the ref at a prior point in time.
You can combine those git diff or git log commands with "Finding most changed files in git":
git log --pretty=format: --name-only | sort | uniq -c | sort -rg | head -10