Pandas data frame : how to check all value of last row if it is non zero-CodePudding

i want to check last row's all value if it is non-zero,if it is non zero then give me column name.

df = pd.DataFrame({'A': [1,2,-2,0,0], 'B': [0, 0, 0, 3, -2], 'C' : [0, 0, -2, 4, 0], 'D': [0, 0, 0, 1, 0]} )

CodePudding user response：

Use:

df.columns[(df.iloc[[-1]] != 0).all()]

Output:

Index(['B'], dtype='object')

If you wish to get only column name then use:

df.columns[(df.iloc[[-1]] != 0).all()][0]

Output:

'B'

Explanation:

This line returns a boolean mask of the last row if the value is non-zero.

(df.iloc[[-1]] != 0).all()
   A     B      C      D
4  False  True  False  False

This line applies the boolean mask to the column names of the data frame.

df.columns[]