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Diffstat (limited to '.venv/lib/python3.12/site-packages/networkx/readwrite/leda.py')
-rw-r--r-- | .venv/lib/python3.12/site-packages/networkx/readwrite/leda.py | 108 |
1 files changed, 108 insertions, 0 deletions
diff --git a/.venv/lib/python3.12/site-packages/networkx/readwrite/leda.py b/.venv/lib/python3.12/site-packages/networkx/readwrite/leda.py new file mode 100644 index 00000000..9fb57db1 --- /dev/null +++ b/.venv/lib/python3.12/site-packages/networkx/readwrite/leda.py @@ -0,0 +1,108 @@ +""" +Read graphs in LEDA format. + +LEDA is a C++ class library for efficient data types and algorithms. + +Format +------ +See http://www.algorithmic-solutions.info/leda_guide/graphs/leda_native_graph_fileformat.html + +""" +# Original author: D. Eppstein, UC Irvine, August 12, 2003. +# The original code at http://www.ics.uci.edu/~eppstein/PADS/ is public domain. + +__all__ = ["read_leda", "parse_leda"] + +import networkx as nx +from networkx.exception import NetworkXError +from networkx.utils import open_file + + +@open_file(0, mode="rb") +@nx._dispatchable(graphs=None, returns_graph=True) +def read_leda(path, encoding="UTF-8"): + """Read graph in LEDA format from path. + + 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.read_leda('file.leda') + + References + ---------- + .. [1] http://www.algorithmic-solutions.info/leda_guide/graphs/leda_native_graph_fileformat.html + """ + lines = (line.decode(encoding) for line in path) + G = parse_leda(lines) + return G + + +@nx._dispatchable(graphs=None, returns_graph=True) +def parse_leda(lines): + """Read graph in LEDA format from string or iterable. + + Parameters + ---------- + lines : string or iterable + Data in LEDA format. + + Returns + ------- + G : NetworkX graph + + Examples + -------- + G=nx.parse_leda(string) + + References + ---------- + .. [1] http://www.algorithmic-solutions.info/leda_guide/graphs/leda_native_graph_fileformat.html + """ + if isinstance(lines, str): + lines = iter(lines.split("\n")) + lines = iter( + [ + line.rstrip("\n") + for line in lines + if not (line.startswith(("#", "\n")) or line == "") + ] + ) + for i in range(3): + next(lines) + # Graph + du = int(next(lines)) # -1=directed, -2=undirected + if du == -1: + G = nx.DiGraph() + else: + G = nx.Graph() + + # Nodes + n = int(next(lines)) # number of nodes + node = {} + for i in range(1, n + 1): # LEDA counts from 1 to n + symbol = next(lines).rstrip().strip("|{}| ") + if symbol == "": + symbol = str(i) # use int if no label - could be trouble + node[i] = symbol + + G.add_nodes_from([s for i, s in node.items()]) + + # Edges + m = int(next(lines)) # number of edges + for i in range(m): + try: + s, t, reversal, label = next(lines).split() + except BaseException as err: + raise NetworkXError(f"Too few fields in LEDA.GRAPH edge {i+1}") from err + # BEWARE: no handling of reversal edges + G.add_edge(node[int(s)], node[int(t)], label=label[2:-2]) + return G |