如何根据Python中的简单条件过滤熊猫数据框？

Question

Simple Question!

I have a Panda Dataframe.

How do I create a new array (dataframe, numpy array or list) that selects all the data on the original dataframe with the value "0" on the first column.

For example If I had:

0, 10, 15
0, 5, 16
2, 5, 9
1, 2, 2

I will have a new filtered list:

0, 10, 15
0, 5, 16 

Answer 1

Just use the index of the column, like so:

In [3]: df = DataFrame([[0,1,2], [0,2,3], [1,2,3]])

In [4]: df
Out[4]:
   0  1  2
0  0  1  2
1  0  2  3
2  1  2  3

In [5]: df[0]
Out[5]:
0    0
1    0
2    1
Name: 0, dtype: int64

In [6]: df[df[0]==0]
Out[6]:
   0  1  2
0  0  1  2
1  0  2  3

Answer 2

import pandas as pd

df = pd.DataFrame({'a': [0, 0, 2, 1], 'b': [10, 5, 5, 2], 'c': [15, 16, 92, 2]})
zero_rows = df[df.iloc[:, 0] == 0]

To index by the column name instead:

zero_rows = df[df['a'] == 0]