“““
This?module?provides?functions?to?convert?
NetworkX?graphs?to?and?from?other?formats.

The?preferred?way?of?converting?data?to?a?NetworkX?graph?
is?through?the?graph?constuctor.??The?constructor?calls
the?to_networkx_graph（）?function?which?attempts?to?guess?the
input?type?and?convert?it?automatically.

Examples
--------

Create?a?10?node?random?graph?from?a?numpy?matrix

>>>?import?numpy
>>>?a=numpy.reshape（numpy.random.random_integers（01size=100）（1010））
>>>?D=nx.DiGraph（a）?

or?equivalently

>>>?D=nx.to_networkx_graph（acreate_using=nx.DiGraph（））?

Create?a?graph?with?a?single?edge?from?a?dictionary?of?dictionaries

>>>?d={0:?{1:?1}}?#?dict-of-dicts?single?edge?（01）
>>>?G=nx.Graph（d）


See?Also
--------
nx_pygraphviz?nx_pydot

“““
__author__?=?“““\n“““.join（[‘Aric?Hagberg?（hagberg@lanl.gov）‘
???????????????????????????‘Pieter?Swart?（swart@lanl.gov）‘
???????????????????????????‘Dan?Schult（dschult@colgate.edu）‘]）
#????Copyright?（C）?2006-2011?by?
#????Aric?Hagberg?
#????Dan?Schult?
#????Pieter?Swart?
#????All?rights?reserved.
#????BSD?license.

import?warnings
import?networkx?as?nx

__all__?=?[‘to_networkx_graph‘
???????????‘from_dict_of_dicts‘?‘to_dict_of_dicts‘
???????????‘from_dict_of_lists‘?‘to_dict_of_lists‘
???????????‘from_edgelist‘?‘to_edgelist‘
???????????‘from_numpy_matrix‘?‘to_numpy_matrix‘
???????????‘to_numpy_recarray‘
???????????‘from_scipy_sparse_matrix‘?‘to_scipy_sparse_matrix‘]

def?_prep_create_using（create_using）:
????“““Return?a?graph?object?ready?to?be?populated.

????If?create_using?is?None?return?the?default?（just?networkx.Graph（））
????If?create_using.clear（）?works?assume?it?returns?a?graph?object.
????Otherwise?raise?an?exception?because?create_using?is?not?a?networkx?graph.

????“““
????if?create_using?is?None:
????????G=nx.Graph（）
????else:
????????G=create_using
????????try:
????????????G.clear（）
????????except:
????????????raise?TypeError（“Input?graph?is?not?a?networkx?graph?type“）
????return?G

def?to_networkx_graph（datacreate_using=Nonemultigraph_input=False）:
????“““Make?a?NetworkX?graph?from?a?known?data?structure.

????The?preferred?way?to?call?this?is?automatically
????from?the?class?constructor

????>>>?d={0:?{1:?{‘weight‘:1}}}?#?dict-of-dicts?single?edge?（01）
????>>>?G=nx.Graph（d）

????instead?of?the?equivalent

????>>>?G=nx.from_dict_of_dicts（d）

????Parameters
????----------
????data?:?a?object?to?be?converted
???????Current?known?types?are:
?????????any?NetworkX?graph
?????????dict-of-dicts
?????????dist-of-lists
?????????list?of?edges
?????????numpy?matrix
?????????numpy?ndarray
?????????scipy?sparse?matrix
?????????pygraphviz?agraph

????create_using?:?NetworkX?graph
???????Use?specified?graph?for?result.??Otherwise?a?new?graph?is?created.

????multigraph_input?:?bool?（default?False）
??????If?True?and??data?is?a?dict_of_dicts
??????try?to?create?a?multigraph?assuming?dict_of_dict_of_lists.
??????If?data?and?create_using?are?bo