condition pandas code example

Example 1: or condition in pandas

df1 = df[(df.a != -1) & (df.b != -1)]

Example 2: or condition in pandas

df2 = df[(df.a != -1) | (df.b != -1)]

Example 3: if condition dataframe python

df.loc[df['age1'] - df['age2'] > 0, 'diff'] = df['age1'] - df['age2']

Example 4: python pandas dataframe conditional subset

In [722]: df[(df['C']==1) | df['B']]
Out[722]:
   A      B  C
0  1   True  1
2  2  False  1
3  2   True  2
4  3   True  1

In [723]: df.query('C==1 or B==True')
Out[723]:
   A      B  C
0  1   True  1
2  2  False  1
3  2   True  2
4  3   True  1

In [724]: df[df.eval('C==1 or B==True')]
Out[724]:
   A      B  C
0  1   True  1
2  2  False  1
3  2   True  2
4  3   True  1