flpq_data.graphs.readwrite.txt#

Read (and write) a graph from (and to) TXT file.

Functions

`graph_from_text`(text)	Returns a graph from text.
`graph_from_txt`(path)	Returns a graph loaded from a TXT file.
`graph_to_text`(graph, *[, quoting])	Turns a graph into its text representation.
`graph_to_txt`(graph, path, *[, quoting])	Returns a path to the TXT file where the graph will be saved.
`iter_edges_from_text`(text)	Yields the edges of a text representation as a stream.
`iter_edges_from_txt`(path)	Yields the edges of a TXT file as a stream.
`txt_from_edges`(edges, path, *[, quoting])	Writes an edge stream to a TXT file.

graph_from_text(text: Iterable[str]) → MultiDiGraph[source]#

Returns a graph from text.

Parameters:

textIterable[str]: The text with which the graph will be created.

Returns:

gMultiDiGraph: Loaded graph.

Examples

>>> from flpq_data import *
>>> g = graph_from_text(["1 A 2"])
>>> g.number_of_nodes()
2
>>> g.number_of_edges()
1

graph_from_txt(path: Path | str) → MultiDiGraph[source]#

Returns a graph loaded from a TXT file.

Parameters:

pathUnion[Path, str]: The path to the TXT file with which the graph will be created.

Returns:

gMultiDiGraph: Loaded graph.

Examples

>>> from flpq_data import *
>>> g_1 = graph_from_text(["1 A 2"])
>>> p = graph_to_txt(g_1, "test.txt")
>>> g = graph_from_txt(p)
>>> g.number_of_nodes()
2
>>> g.number_of_edges()
1

graph_to_text(graph: MultiDiGraph, *, quoting: bool = False) → Iterator[str][source]#

Turns a graph into its text representation.

One line per edge; the label is taken from the edge’s label attribute (the same convention as graph_to_mtx_dir).

Parameters:

graphMultiDiGraph: Graph to text.
quotingbool: If true, quotes will be added.

Returns:

textstr: Generator of graph edges.

Examples

>>> from flpq_data import *
>>> g = labeled_cycle_graph(2)
>>> list(graph_to_text(g, quoting=True))
["'0' 'a' '1'", "'1' 'a' '0'"]
>>> list(graph_to_text(g, quoting=False))
['0 a 1', '1 a 0']

graph_to_txt(graph: MultiDiGraph, path: Path | str, *, quoting: bool = False) → Path[source]#

Returns a path to the TXT file where the graph will be saved.

Parameters:

graphMultiDiGraph: Graph to save.
path: Union[Path, str]: The path to the file where the graph will be saved.
quotingbool: If true, quotes will be added.

Returns:

pathPath: Path to a TXT file where the graph will be saved.

Examples

>>> from flpq_data import *
>>> g = labeled_cycle_graph(42, label="a")
>>> path = graph_to_txt(g, "test.txt", quoting=False)

iter_edges_from_text(text: Iterable[str]) → Iterator[Tuple[str, str, str]][source]#

Yields the edges of a text representation as a stream.

Each line is FROM LABEL TO — three whitespace-separated tokens; quoting is allowed, as in shell syntax.

Parameters:

textIterable[str]: The lines with which the edges will be created.

Returns:

edgesIterator[Tuple[str, str, str]]: The (u, label, v) edge tuples in line order.

Raises:

ValueError: If a line does not match the FROM LABEL TO format.

Examples

>>> list(iter_edges_from_text(["1 A 2", "'3' 'b_5' '4'"]))
[('1', 'A', '2'), ('3', 'b_5', '4')]

iter_edges_from_txt(path: Path | str) → Iterator[Tuple[str, str, str]][source]#

Yields the edges of a TXT file as a stream.

The file holds one FROM LABEL TO edge per line (see iter_edges_from_text()).

Parameters:

pathUnion[Path, str]: The path to the TXT file with which the edges will be created.

Returns:

edgesIterator[Tuple[str, str, str]]: The (u, label, v) edge tuples in line order.

Examples

>>> import pathlib, tempfile
>>> p = pathlib.Path(tempfile.mkdtemp()) / "g.txt"
>>> _ = p.write_text("1 A 2\n3 b_5 4\n")
>>> list(iter_edges_from_txt(p))
[('1', 'A', '2'), ('3', 'b_5', '4')]

txt_from_edges(edges: Iterable[Tuple[str, str, str]], path: Path | str, *, quoting: bool = False) → Path[source]#

Writes an edge stream to a TXT file.

One FROM LABEL TO line per edge (the format of iter_edges_from_text()); the memory stays O(1) in the number of edges.

Parameters:

edgesIterable[Tuple[str, str, str]]: The (u, label, v) edge tuples to write.
pathUnion[Path, str]: The path to the TXT file where the edges will be saved.
quotingbool: If true, quotes will be added.

Returns:

pathPath: Path to the TXT file where the edges will be saved.

Examples

>>> import pathlib, tempfile
>>> p = pathlib.Path(tempfile.mkdtemp()) / "g.txt"
>>> _ = txt_from_edges([("1", "A", "2")], p)
>>> p.read_text()
'1 A 2\n'