plydata.one_table_verbs.sample_frac

class plydata.one_table_verbs.sample_frac(*args, **kwargs)[source]

Sample a fraction of rows from dataframe

Parameters
datadataframe, optional

Useful when not using the >> operator.

fracfloat, optional

Fraction of axis items to return. Cannot be used with n.

replaceboolean, optional

Sample with or without replacement. Default = False.

weightsstr or ndarray-like, optional

Default 'None' results in equal probability weighting. If passed a Series, will align with target object on index. Index values in weights not found in sampled object will be ignored and index values in sampled object not in weights will be assigned weights of zero. If called on a DataFrame, will accept the name of a column when axis = 0. Unless weights are a Series, weights must be same length as axis being sampled. If weights do not sum to 1, they will be normalized to sum to 1. Missing values in the weights column will be treated as zero. inf and -inf values not allowed.

random_stateint or numpy.random.RandomState, optional

Seed for the random number generator (if int), or numpy RandomState object.

axisint or string, optional

Axis to sample. Accepts axis number or name. Default is stat axis for given data type (0 for Series and DataFrames, 1 for Panels).

Examples

>>> import pandas as pd
>>> import numpy as np
>>> rs = np.random.RandomState(1234567890)
>>> df = pd.DataFrame({'x': range(20)})
>>> df >> sample_frac(0.25, random_state=rs)
     x
5    5
19  19
14  14
8    8
17  17