U md'@sdZddlZddlmZddlmZmZddlm Z m Z dddd gZ d d Z d dZ dddZe dddddZe de dddddd ZdS)aPFunctions 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: https://users.cecs.anu.edu.au/~bdm/data/formats.html N) NetworkXError) data_to_n n_to_data)not_implemented_for open_filefrom_sparse6_bytes read_sparse6to_sparse6_bytes write_sparse6c #st|}|dkrtd|r"dVdVt|D]}tt|dVq0dd>|krdd7qNfdd}td d |D}gd }|D]\}} ||krd  || q||dkr|d7}d || q|}d ||d  || qd kr|d>krt d kr||dkrd  dgt d n dgt d fd dt d td D} | D]}tt|dVqdVdS)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 ** 36 >>sparse6<<:?csfddtDS)zBig endian k-bit encoding of xcs(g|] }dd|>@r dndqS)rr.0i)kxrS/home/sam/Atlas/atlas_env/lib/python3.8/site-packages/networkx/readwrite/sparse6.py <sz8_generate_sparse6_bytes..enc..)ranger)rrrenc:sz$_generate_sparse6_bytes..enccss&|]\}}t||t||fVqdS)N)maxmin)ruvrrr >sz*_generate_sparse6_bytes..rcslg|]d}|dd>|dd>|dd>|dd>|dd>|dd>qS)rrrr)bitsrrrYsz+_generate_sparse6_bytes.. N) len ValueErrorrstrencodechrsortededgesappendextendr) Gnodesheaderndrr,Zcurvrrdatar)r$rr_generate_sparse6_bytessP          :   r5c s|dr|dd}|ds(tddd|ddD}t|\}dd>|krdd7qNfd d }d }t}|t|d }|D]X\}}|dkr|d7}||ks||krqq||kr|}q|||rd }|||q|st |}|S)aVRead 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 r Nr z!Expected leading colon in sparse6cSsg|] }|dqS)r r)rcrrrrsz&from_sparse6_bytes..rc3st}d}d}|dkr@z t|}Wntk r:YdSXd}|d8}||?d@}|d|>d@}|}|krz t|}Wntk rYdSXd}|d>|}|d7}qh||?}|}||fVqdS)z6Returns stream of pairs b[i], x[i] for sparse6 format.Nrrr)iternext StopIteration)chunksr3ZdLenbrZxLenr4rrr parseDatas0      z%from_sparse6_bytes..parseDatarFT) startswithrrnxZ MultiGraphZadd_nodes_fromrZhas_edgeZadd_edgeZGraph) stringcharsr2r>rr/Z multigraphr<rrr=rrhs6!        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)) 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+Zordering)subgraphr@convert_node_labels_to_integersjoinr5)r/r0r1rrrr s, rb)modecCsJg}|D]$}|}t|sq|t|qt|dkrB|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(delete=False) 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 ZdirectedrwbcCs@|dk r||}tj|dd}t|||D]}||q,dS)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(delete=False) 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+rC)rEr@rFr5write)r/rKr0r1r<rrrr :s 8 )NT)NT)__doc__Znetworkxr@Znetworkx.exceptionrZnetworkx.readwrite.graph6rrZnetworkx.utilsrr__all__r5rr rr rrrrs   Ra 2  >