dependency graph.py

import graphviz
import pkg_resources
pkg_keys = {}
for item in pkg_resources.working_set:
    r = item.as_requirement()
    pkg_keys[r.key] = r.project_name

depends = {}
for item in pkg_resources.working_set:
    depends[item.as_requirement().key] = [r.key for r in item.requires()]

# so from here you could do a lot of interesting things with the depends dict
# here we'll just make a pretty unreadable graphviz dotfile

dot = graphviz.Digraph(comment="dependencies")
for pkg_key, pkg_name in pkg_keys.items():
    dot.node(pkg_key, pkg_name)

for pkg_key, dependencies in depends.items():
    for dependency in dependencies:
        dot.edge(pkg_key, dependency)

print dot.source