TOMS097 is a Python library which computes the distance between all pairs of nodes in a directed graph with weighted edges, using Floyd's algorithm.
The computer code and data files made available on this web page are distributed under the GNU LGPL license.
TOMS097 is available in a C version and a C++ version and a FORTRAN77 version and a FORTRAN90 version and a MATLAB version and a Python version.
BELLMAN_FORD, a Python library which implements the Bellman-Ford algorithm for finding the shortest distance from a given node to all other nodes in a directed graph whose edges have been assigned real-valued lengths.
DIJKSTRA, a Python program which runs a simple example of Dijkstra's minimum distance algorithm for graphs.
You can go up one level to the Python source codes.