Random Sample of a subset of a dataframe in Pandas

Question

Say i have a dataframe with 100,000 entries and want to split it into 100 sections of 1000 entries.

How do i take a random sample of say size 50 of just one of the

Answer 1

You can use the sample method*:

In [11]: df = pd.DataFrame([[1, 2], [3, 4], [5, 6], [7, 8]], columns=["A", "B"])

In [12]: df.sample(2)
Out[12]:
   A  B
0  1  2
2  5  6

In [13]: df.sample(2)
Out[13]:
   A  B
3  7  8
0  1  2

*On one of the section DataFrames.

Note: If you have a larger sample size that the size of the DataFrame this will raise an error unless you sample with replacement.

In [14]: df.sample(5)
ValueError: Cannot take a larger sample than population when 'replace=False'

In [15]: df.sample(5, replace=True)
Out[15]:
   A  B
0  1  2
1  3  4
2  5  6
3  7  8
1  3  4