1. The fastnumbers module

Super-fast and clean conversions to numbers.

Please see the Timing Documentation for timing details. Check out the API.

1.1. Quick Description

The below examples showcase the fast_float() function, which is a fast conversion functions with error-handling. Please see the API Documentation for other functions that are available from fastnumbers.

>>> from fastnumbers import fast_float, float as fnfloat
>>> # Convert string to a float
>>> fast_float('56.07')
>>> # Unconvertable string returned as-is by default
>>> fast_float('bad input')
'bad input'
>>> # Unconvertable strings can trigger a default value
>>> fast_float('bad input', default=0)
>>> # 'default' is also the first optional positional arg
>>> fast_float('bad input', 0)
>>> # Integers are converted to floats
>>> fast_float(54)
>>> # One can ask inf or nan to be substituted with another value
>>> fast_float('nan')
>>> fast_float('nan', nan=0.0)
>>> fast_float(float('nan'), nan=0.0)
>>> fast_float('56.07', nan=0.0)
>>> # The default built-in float behavior can be triggered with
>>> # "raise_on_invalid" set to True.
>>> fast_float('bad input', raise_on_invalid=True) 
Traceback (most recent call last):
ValueError: invalid literal for float(): bad input
>>> # A key function can be used to return an alternate value for invalid input
>>> fast_float('bad input', key=len)
>>> fast_float(54, key=len)
>>> # Single unicode characters can be converted.
>>> fast_float(u'\u2164')  # Roman numeral 5 (V)
>>> fast_float(u'\u2466')  # 7 enclosed in a circle

NOTE: If you need locale-dependent conversions, supply the fastnumbers function of your choice to locale.atof().

import locale
locale.setlocale(locale.LC_ALL, 'de_DE.UTF-8')
print(atof('468,5', func=fast_float))  # Prints 468.5

1.2. Installation

Installation of fastnumbers is ultra-easy. Simply execute from the command line:

easy_install fastnumbers

or, if you have pip (preferred over easy_install):

pip install fastnumbers

Both of the above commands will download the source for you.

You can also download the source from https://pypi.org/project/fastnumbers/, or browse the git repository at https://github.com/SethMMorton/fastnumbers.

If you choose to install from source (will need a C compiler and the Python headers), you can unzip the source archive and enter the directory, and type:

python setup.py install

If you wish to run the unit tests, enter:

python setup.py test

If you want to build this documentation, enter:

python setup.py build_sphinx

fastnumbers requires python version 2.6 or greater (this includes python 3.x). Unit tests are only run on 2.6, 2.7 and >= 3.3.