pyrevit.coreutils.pyutils

Usage

from pyrevit.coreutils import pyutils
pyutils.safe_cast('string', int, 0)

Documentation

Helper functions for python.

pyrevit.coreutils.pyutils.isnumber(token)

Verify if given string token is int or float.

Parameters:token (str) – string value Returns:True of token is int or float Return type:bool

Example

>>> isnumber('12.3')
True

pyrevit.coreutils.pyutils.pairwise(iterable, step=2)

Iterate through items in pairs.

Parameters:

• iterable (iterable) – any iterable object
• step (int) – number of steps to move when making pairs

Returns:

list of pairs

Return type:

iterable

Example

>>> pairwise([1, 2, 3, 4, 5])
[(1, 2), (3, 4)]    # 5 can not be paired
>>> pairwise([1, 2, 3, 4, 5, 6])
[(1, 2), (3, 4), (5, 6)]
>>> pairwise([1, 2, 3, 4, 5, 6], step=1)
[(1, 2), (2, 3), (3, 4), (4, 5), (5, 6)]

pyrevit.coreutils.pyutils.safe_cast(val, to_type, default=None)

Convert value to type gracefully.

This method basically calls to_type(value) and returns the default if exception occurs.

Parameters:

• val (any) – value to be converted
• to_type (type) – target type
• default (any) – value to rerun on conversion exception

Example

>>> safe_cast('name', int, default=0)
0

Implementation

"""Helper functions for python."""

import re


def pairwise(iterable, step=2):
    """Iterate through items in pairs.

    Args:
        iterable (iterable): any iterable object
        step (int): number of steps to move when making pairs

    Returns:
        iterable: list of pairs

    Example:
        >>> pairwise([1, 2, 3, 4, 5])
        [(1, 2), (3, 4)]    # 5 can not be paired
        >>> pairwise([1, 2, 3, 4, 5, 6])
        [(1, 2), (3, 4), (5, 6)]
        >>> pairwise([1, 2, 3, 4, 5, 6], step=1)
        [(1, 2), (2, 3), (3, 4), (4, 5), (5, 6)]
    """
    if step == 1:
        from itertools import tee, izip
        a, b = tee(iterable)
        next(b, None)
        return izip(a, b)
    elif step == 2:
        a = iter(iterable)
        return zip(a, a)


def safe_cast(val, to_type, default=None):
    """Convert value to type gracefully.

    This method basically calls to_type(value) and returns the default
    if exception occurs.

    Args:
        val (any): value to be converted
        to_type (type): target type
        default (any): value to rerun on conversion exception

    Example:
        >>> safe_cast('name', int, default=0)
        0
    """
    try:
        return to_type(val)
    except (ValueError, TypeError):
        return default


def isnumber(token):
    """Verify if given string token is int or float.

    Args:
        token (str): string value

    Returns:
        bool: True of token is int or float

    Example:
        >>> isnumber('12.3')
        True
    """
    return re.match("^[0-9.]+?$", token) is not None