Class PythonRandomInterface

networkx/utils/misc.py:359–435

PythonRandomInterface is included for backward compatibility New code should use PythonRandomViaNumpyBits instead.

##################################################################
class PythonRandomInterface:
    """PythonRandomInterface is included for backward compatibility
    New code should use PythonRandomViaNumpyBits instead.
    """

    def __init__(self, rng=None):
        try:
            import numpy as np
        except ImportError:
            msg = "numpy not found, only random.random available."
            warnings.warn(msg, ImportWarning)

        if rng is None:
            self._rng = np.random.mtrand._rand
        else:
            self._rng = rng

    def random(self):
        return self._rng.random()

    def uniform(self, a, b):
        return a + (b - a) * self._rng.random()

    def randrange(self, a, b=None):
        import numpy as np

        if b is None:
            a, b = 0, a
        if b > 9223372036854775807:  # from np.iinfo(np.int64).max
            tmp_rng = PythonRandomViaNumpyBits(self._rng)
            return tmp_rng.randrange(a, b)

        if isinstance(self._rng, np.random.Generator):
            return self._rng.integers(a, b)
        return self._rng.randint(a, b)

    # NOTE: the numpy implementations of `choice` don't support strings, so
    # this cannot be replaced with self._rng.choice
    def choice(self, seq):
        import numpy as np

        if isinstance(self._rng, np.random.Generator):
            idx = self._rng.integers(0, len(seq))
        else:
            idx = self._rng.randint(0, len(seq))
        return seq[idx]

    def gauss(self, mu, sigma):
        return self._rng.normal(mu, sigma)

    def shuffle(self, seq):
        return self._rng.shuffle(seq)

    #    Some methods don't match API for numpy RandomState.
    #    Commented out versions are not used by NetworkX

    def sample(self, seq, k):
        return self._rng.choice(list(seq), size=(k,), replace=False)