graph-tool is an efficient python module for manipulation and statistical analysis of graphs.
Despite its nice, soft outer appearance of a regular python module, the core algorithms and data structures of graph-tool are written in C++, making use of the Boost Graph Library and template metaprogramming, with performance in mind. Most of the time, you can expect the algorithms to run just as fast as if graph-tool were a pure C++ library.
It contains several algorithms present in the Boost Graph Library, and many others, such as random graph generation (with arbitrary degree sequence and correlations), clustering, motifs, community detection, graph randomization, subgraph isomorphism, etc.
