B ,[)@sdZddlmZddlZddlZddlZddlmZddl m Z m Z ddl m Z mZddd d gZd d Zd dZddd Ze dddddZe de dddddd ZdS)aOFunctions for reading and writing graphs in the *sparse6* format. The *sparse6* file format is a space-efficient format for large sparse graphs. For small graphs or large dense graphs, use the *graph6* file format. For more information, see the `sparse6`_ homepage. .. _sparse6: http://users.cecs.anu.edu.au/~bdm/data/formats.html )chainN) NetworkXError) open_filenot_implemented_for) data_to_n n_to_datafrom_sparse6_bytes read_sparse6to_sparse6_bytes write_sparse6c #st|}|dkrtd|r"dVdVx$t|D]}tt|dVq2Wdxd>|krjd7qTWfdd}td d |D}gd }x|D]\}} ||krƈd  || q||dkr|d7}d || q|}d ||d  || qWd kr|d>krt d kr||dkrd  dgt d n dgt d fd dt d td D} x"| D]}tt|dVqWdVdS)a%Yield bytes in the sparse6 encoding of a graph. `G` is an undirected simple graph. `nodes` is the list of nodes for which the node-induced subgraph will be encoded; if `nodes` is the list of all nodes in the graph, the entire graph will be encoded. `header` is a Boolean that specifies whether to generate the header ``b'>>sparse6<<'`` before the remaining data. This function generates `bytes` objects in the following order: 1. the header (if requested), 2. the encoding of the number of nodes, 3. each character, one-at-a-time, in the encoding of the requested node-induced subgraph, 4. a newline character. This function raises :exc:`ValueError` if the graph is too large for the graph6 format (that is, greater than ``2 ** 36`` nodes). l@z?sparse6 is only defined if number of nodes is less than 2 ** 36s >>sparse6<<:?csfddtDS)zBig endian k-bit encoding of xcs(g|] }dd|>@r dndqS)rr).0i)kxr9lib/python3.7/site-packages/networkx/readwrite/sparse6.py Jsz8_generate_sparse6_bytes..enc..)range)r)r)rrencHsz$_generate_sparse6_bytes..enccss&|]\}}t||t||fVqdS)N)maxmin)ruvrrr Lsz*_generate_sparse6_bytes..rcslg|]d}|dd>|dd>|dd>|dd>|dd>|dd>qS)rrr)rr)bitsrrrgsz+_generate_sparse6_bytes.. N) len ValueErrorrstrencodechrsortededgesappendextendr) Gnodesheaderndrr*Zcurvrrdatar)r"rr_generate_sparse6_bytes%sJ       :   r3c s.|dr|dd}|ds(tdtjdkrJdd|d dD}nd d|d dD}t|\}d xd >|krd 7qrWfd d }d }t}|t|d}xb|D]X\}}|d kr|d 7}||ks||krPq||kr|}q| ||r d}| ||qW|s*t |}|S)aURead an undirected graph in sparse6 format from string. Parameters ---------- string : string Data in sparse6 format Returns ------- G : Graph Raises ------ NetworkXError If the string is unable to be parsed in sparse6 format Examples -------- >>> G = nx.from_sparse6_bytes(b':A_') >>> sorted(G.edges()) [(0, 1), (0, 1), (0, 1)] See Also -------- read_sparse6, write_sparse6 References ---------- .. [1] Sparse6 specification s >>sparse6<< Nr z!Expected leading colon in sparse6)r!cSsg|]}t|dqS)r )ord)rcrrrrsz&from_sparse6_bytes..rcSsg|] }|dqS)r r)rr6rrrrsc3st}d}d}x|dkr@y t|}Wntk r:dSXd}|d8}||?d@}|d|>d@}|}xF|kry t|}Wntk rdSXd}|d>|}|d7}qjW||?}|}||fVqWdS)z5Return stream of pairs b[i], x[i] for sparse6 format.Nrrr)iternext StopIteration)Zchunksr1ZdLenbrZxLen)r2rrr parseDatas2       z%from_sparse6_bytes..parseDatarFT) startswithrsys version_infornxZ MultiGraphZadd_nodes_fromrZhas_edgeZadd_edgeZGraph) stringcharsr0r;rr-Z multigraphr:rr)r2rrros:!       TcCs2|dk r||}tj|dd}dt|||S)aConvert an undirected graph to bytes in sparse6 format. Parameters ---------- G : Graph (undirected) nodes: list or iterable Nodes are labeled 0...n-1 in the order provided. If None the ordering given by ``G.nodes()`` is used. header: bool If True add '>>sparse6<<' bytes to head of data. Raises ------ NetworkXNotImplemented If the graph is directed. ValueError If the graph has at least ``2 ** 36`` nodes; the sparse6 format is only defined for graphs of order less than ``2 ** 36``. Examples -------- >>> nx.to_sparse6_bytes(nx.path_graph(2)) # doctest: +SKIP b'>>sparse6<<:An\n' See Also -------- to_sparse6_bytes, read_sparse6, write_sparse6_bytes Notes ----- The returned bytes end with a newline character. The format does not support edge or node labels. References ---------- .. [1] Graph6 specification Nr))ordering)subgraphr?convert_node_labels_to_integersjoinr3)r-r.r/rrrr s, rb)modecCsNg}x,|D]$}|}t|s q |t|q Wt|dkrF|dS|SdS)aRead an undirected graph in sparse6 format from path. Parameters ---------- path : file or string File or filename to write. Returns ------- G : Graph/Multigraph or list of Graphs/MultiGraphs If the file contains multiple lines then a list of graphs is returned Raises ------ NetworkXError If the string is unable to be parsed in sparse6 format Examples -------- You can read a sparse6 file by giving the path to the file:: >>> import tempfile >>> with tempfile.NamedTemporaryFile() as f: ... _ = f.write(b'>>sparse6<<:An\n') ... _ = f.seek(0) ... G = nx.read_sparse6(f.name) >>> list(G.edges()) [(0, 1)] You can also read a sparse6 file by giving an open file-like object:: >>> import tempfile >>> with tempfile.NamedTemporaryFile() as f: ... _ = f.write(b'>>sparse6<<:An\n') ... _ = f.seek(0) ... G = nx.read_sparse6(f) >>> list(G.edges()) [(0, 1)] See Also -------- read_sparse6, from_sparse6_bytes References ---------- .. [1] Sparse6 specification rrN)stripr$r+r)pathZglistlinerrrr s3  ZdirectedrwbcCsD|dk r||}tj|dd}xt|||D]}||q.WdS)a3Write graph G to given path in sparse6 format. Parameters ---------- G : Graph (undirected) path : file or string File or filename to write nodes: list or iterable Nodes are labeled 0...n-1 in the order provided. If None the ordering given by G.nodes() is used. header: bool If True add '>>sparse6<<' string to head of data Raises ------ NetworkXError If the graph is directed Examples -------- You can write a sparse6 file by giving the path to the file:: >>> import tempfile >>> with tempfile.NamedTemporaryFile() as f: ... nx.write_sparse6(nx.path_graph(2), f.name) ... print(f.read()) # doctest: +SKIP b'>>sparse6<<:An\n' You can also write a sparse6 file by giving an open file-like object:: >>> with tempfile.NamedTemporaryFile() as f: ... nx.write_sparse6(nx.path_graph(2), f) ... _ = f.seek(0) ... print(f.read()) # doctest: +SKIP b'>>sparse6<<:An\n' See Also -------- read_sparse6, from_sparse6_bytes Notes ----- The format does not support edge or node labels. References ---------- .. [1] Sparse6 specification Nr))rB)rDr?rEr3write)r-rJr.r/r:rrrr Ds 8 )NT)NT)__doc__ itertoolsrZmathr=Znetworkxr?Znetworkx.exceptionrZnetworkx.utilsrrZnetworkx.readwrite.graph6rr__all__r3rr r r rrrrs   Jd 2?