3 d'@sdZddlZddlmZddlmZmZddlm Z m Z dddd gZ d d Z d dZ dddZedddddZededddddd 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 N) 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]}tjt|dVq2Wdxd>|krjd7qTWfdd }td d |jD}gd }x|D]\}} ||krƈjd j || q||dkr|d7}jdj || q|}jdj ||jd j || qWd kr|d>krt d kr||dkrjd j dgt d nj dgt d fddt d td D} x"| D]}tjt|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). $z?sparse6 is only defined if number of nodes is less than 2 ** 36s >>sparse6<<:?csfddtDS)zBig endian k-bit encoding of xcs(g|] }dd|>@r dndqS)rr).0i)kxr>/tmp/pip-build-7vycvbft/networkx/networkx/readwrite/sparse6.py <sz8_generate_sparse6_bytes..enc..)range)r)r)rrenc:sz$_generate_sparse6_bytes..enccss&|]\}}t||t||fVqdS)N)maxmin)ruvrrr >sz*_generate_sparse6_bytes..rcslg|]d}|dd>|dd>|dd>|dd>|dd>|dd>qS)rrr r)rr)bitsrrrZsz+_generate_sparse6_bytes.. Nl@) len ValueErrorrstrencodechrsortededgesappendextendr) Gnodesheaderndrr*Zcurvrrdatar)r"rr_generate_sparse6_bytessL       :   r3c s |jdr|dd}|jds(tddd|ddD}t|\}dxd>|krfd7qPWfd d }d }tj}|jt|d }x`|D]V\}}|dkr|d7}||ks||krPq||kr|}q|j||rd }|j||qW|stj |}|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 sparse6cSsg|] }|dqS)rr)rcrrrrsz&from_sparse6_bytes..rc3st}d}d}x|dkr@y t|}Wntk r:dSXd}|d8}||?d@}|d|>d@}|}xF|kry t|}Wntk rdSXd}|d>|}|d7}qjW||?}|}||fVqWdS)z6Returns stream of pairs b[i], x[i] for sparse6 format.Nrrr)iternext StopIteration)chunksr1ZdLenbrZxLen)r2rrr parseDatas2       z%from_sparse6_bytes..parseDatarFT) startswithrrnxZ MultiGraphZadd_nodes_fromrZhas_edgeZadd_edgeZGraph) stringcharsr0r;rr-Z multigraphr:rr)r2rrrhs6!       TcCs2|dk r|j|}tj|dd}djt|||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)) 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]$}|j}t|s q |jt|q Wt|dkrF|dS|SdS)aRead an undirected graph in sparse6 format from path. Parameters ---------- path : file or string File or filename to write. Returns ------- G : Graph/Multigraph or list of Graphs/MultiGraphs If the file contains multiple lines then a list of graphs is returned Raises ------ NetworkXError If the string is unable to be parsed in sparse6 format Examples -------- You can read a sparse6 file by giving the path to the file:: >>> import tempfile >>> with tempfile.NamedTemporaryFile() as f: ... _ = f.write(b">>sparse6<<:An\n") ... _ = f.seek(0) ... G = nx.read_sparse6(f.name) >>> list(G.edges()) [(0, 1)] You can also read a sparse6 file by giving an open file-like object:: >>> import tempfile >>> with tempfile.NamedTemporaryFile() as f: ... _ = f.write(b">>sparse6<<:An\n") ... _ = f.seek(0) ... G = nx.read_sparse6(f) >>> list(G.edges()) [(0, 1)] See Also -------- read_sparse6, from_sparse6_bytes References ---------- .. [1] Sparse6 specification rrN)stripr$r+r)pathZglistlinerrrrs3  ZdirectedrwbcCsD|dk r|j|}tj|dd}xt|||D]}|j|q.WdS)aWrite 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()) 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()) 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))r@)rBr=rCr3write)r-rHr.r/r:rrrr :s 8 )NT)NT)__doc__Znetworkxr=Znetworkx.exceptionrZnetworkx.utilsrrZnetworkx.readwrite.graph6rr__all__r3rr rr rrrr s  Ra 2?