~ubuntu-branches/ubuntu/saucy/python-networkx/saucy

"""

****

YAML

****

Read and write NetworkX graphs in YAML format.

"YAML is a data serialization format designed for human readability 

and interaction with scripting languages."

See http://www.yaml.org for documentation.

Format

------

http://pyyaml.org/wiki/PyYAML

"""

__author__ = """Aric Hagberg (hagberg@lanl.gov)"""

#    Copyright (C) 2004-2010 by 

#    Aric Hagberg <hagberg@lanl.gov>

#    Dan Schult <dschult@colgate.edu>

#    Pieter Swart <swart@lanl.gov>

#    All rights reserved.

#    BSD license.

__all__ = ['read_yaml', 'write_yaml']

import networkx as nx

from networkx.utils import open_file

@open_file(1,mode='w')

def write_yaml(G, path, encoding='UTF-8', **kwds):

    """Write graph G in YAML format to path. 

    YAML is a data serialization format designed for human readability 

    and interaction with scripting languages [1]_.

    Parameters

    ----------

    G : graph

       A NetworkX graph

    path : file or string

       File or filename to write. 

       Filenames ending in .gz or .bz2 will be compressed.

    encoding: string, optional

       Specify which encoding to use when writing file.

    Examples

    --------

    >>> G=nx.path_graph(4)

    >>> nx.write_yaml(G,'test.yaml')

    References

    ----------

    .. [1] http://www.yaml.org

    """

    try:

        import yaml

    except ImportError:

        raise ImportError("write_yaml() requires PyYAML: http://pyyaml.org/")

    yaml.dump(G, path, **kwds)

@open_file(0,mode='r')

def read_yaml(path):

    """Read graph in YAML format from path.

    YAML is a data serialization format designed for human readability 

    and interaction with scripting languages [1]_.

    Parameters

    ----------

    path : file or string

       File or filename to read.  Filenames ending in .gz or .bz2 

       will be uncompressed.

    Returns

    -------

    G : NetworkX graph

    Examples

    --------

    >>> G=nx.path_graph(4)

    >>> nx.write_yaml(G,'test.yaml')

    >>> G=nx.read_yaml('test.yaml')

    References

    ----------

    .. [1] http://www.yaml.org

    """

    try:

        import yaml

    except ImportError:

        raise ImportError("read_yaml() requires PyYAML: http://pyyaml.org/")

    G=yaml.load(path)

    return G

# fixture for nose tests

def setup_module(module):

    from nose import SkipTest

    try:

        import yaml

    except:

        raise SkipTest("PyYAML not available")

# fixture for nose tests

def teardown_module(module):

    import os

    os.unlink('test.yaml')