== Developer Basics ==

This page has some basic code examples to get you started hacking on hg. See also MercurialApi.

=== Looking at changesets ===

Here's some simple code to look at a [[ChangeSet|changeset]]:

{{{#!python
from mercurial import ui, hg

u = ui.ui()  # get a ui object
r = hg.repository(u, ".") # get a repo object for the current directory
c = r.changectx("tip") # get a context object for the "tip" revision

# show some information about the changeset
print c # represented as the changeset hash
print c.user()
print c.description()
print

# let's take a peek at the files
files = c.files()
for f in files:
 fc = c[f]
 print " ", f, len(fc.data())

}}}

And the output looks like this:

{{{
$ python lc.py
534ec2689c94
Matt Mackall <mpm@selenic.com>
copy: more cleanups

- remove copyfile src variable
- add some comments
- simplify actual copy logic
- simplify 'undelete' logic
- make the error counting actually work

  mercurial/cmdutil.py 41944
}}}
----
CategoryDeveloper