Utilities¶
Helper Functions¶
Miscellaneous Helpers for NetworkX.
These are not imported into the base networkx namespace but can be accessed, for example, as
>>> import networkx
>>> networkx.utils.is_string_like('spam')
True
is_string_like(obj) |
Check if obj is string. |
flatten(obj[, result]) |
Return flattened version of (possibly nested) iterable object. |
iterable(obj) |
Return True if obj is iterable with a well-defined len(). |
is_list_of_ints(intlist) |
Return True if list is a list of ints. |
make_str(x) |
Return the string representation of t. |
generate_unique_node() |
Generate a unique node label. |
default_opener(filename) |
Opens filename using system’s default program. |
pairwise(iterable[, cyclic]) |
s -> (s0, s1), (s1, s2), (s2, s3), … |
groups(many_to_one) |
Converts a many-to-one mapping into a one-to-many mapping. |
create_random_state([random_state]) |
Returns a numpy.random.RandomState instance depending on input. |
Data Structures and Algorithms¶
Union-find data structure.
UnionFind.union(*objects) |
Find the sets containing the objects and merge them all. |
Random Sequence Generators¶
Utilities for generating random numbers, random sequences, and random selections.
powerlaw_sequence(n[, exponent]) |
Return sample sequence of length n from a power law distribution. |
cumulative_distribution(distribution) |
Return normalized cumulative distribution from discrete distribution. |
discrete_sequence(n[, distribution, …]) |
Return sample sequence of length n from a given discrete distribution or discrete cumulative distribution. |
zipf_rv(alpha[, xmin, seed]) |
Return a random value chosen from the Zipf distribution. |
random_weighted_sample(mapping, k) |
Return k items without replacement from a weighted sample. |
weighted_choice(mapping) |
Return a single element from a weighted sample. |
Decorators¶
open_file(path_arg[, mode]) |
Decorator to ensure clean opening and closing of files. |
not_implemented_for(*graph_types) |
Decorator to mark algorithms as not implemented |
nodes_or_number(which_args) |
Decorator to allow number of nodes or container of nodes. |
preserve_random_state(func) |
Decorator to preserve the numpy.random state during a function. |
random_state(random_state_index) |
Decorator to generate a numpy.random.RandomState instance. |
Cuthill-Mckee Ordering¶
Cuthill-McKee ordering of graph nodes to produce sparse matrices
cuthill_mckee_ordering(G[, heuristic]) |
Generate an ordering (permutation) of the graph nodes to make a sparse matrix. |
reverse_cuthill_mckee_ordering(G[, heuristic]) |
Generate an ordering (permutation) of the graph nodes to make a sparse matrix. |