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This article is a reminder of the following information regarding pandas.
- How to delete all 0 columns
- How to delete even one 0 columns
- How to delete all 0 rows
- How to delete even one 0 rows
The policy is to use python’s built-in functions, all() and any(), to identify the rows and columns, and drop to delete the corresponding rows and columns.
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How to delete all 0 columns
import pandas as pd
df = pd.DataFrame({'A':[1,2,3],'B':[0,0,0],'C':[4,0,5],'D':[6,7,8]})
def remove_all_zero_col(df):
df = df.copy()
for col in df.columns:
if (df[col] == 0).all():
df.drop(col, axis=1, inplace=True)
return df
print('before')
print(df)
df = remove_all_zero_col(df)
print('after')
print(df)# Output
before
A B C D
0 1 0 4 6
1 2 0 0 7
2 3 0 5 8
after
A C D
0 1 4 6
1 2 0 7
2 3 5 8How to delete even one 0 column
import pandas as pd
df = pd.DataFrame({'A':[1,2,3],'B':[0,0,0],'C':[4,0,5],'D':[6,7,8]})
def remove_any_zero_col(df):
df = df.copy()
for col in df.columns:
if (df[col] == 0).any():
df.drop(col, axis=1, inplace=True)
return df
print('before')
print(df)
df = remove_any_zero_col(df)
print('after')
print(df)# Output
before
A B C D
0 1 0 4 6
1 2 0 0 7
2 3 0 5 8
after
A D
0 1 6
1 2 7
2 3 8How to delete all 0 rows
import pandas as pd
df = pd.DataFrame({'A':[1,0,2,3],'B':[4,0,0,5],'C':[6,0,0,7]})
def remove_all_zero_row(df):
df = df.copy()
for row in df.index:
if (df.loc[row] == 0).all():
df.drop(row, axis=0, inplace=True)
return df
print('before')
print(df)
df = remove_all_zero_row(df)
print('after')
print(df)# Output
before
A B C
0 1 4 6
1 0 0 0
2 2 0 0
3 3 5 7
after
A B C
0 1 4 6
2 2 0 0
3 3 5 7How to delete even one 0 rows
import pandas as pd
df = pd.DataFrame({'A':[1,0,2,3],'B':[4,0,0,5],'C':[6,0,0,7]})
def remove_any_zero_row(df):
df = df.copy()
for row in df.index:
if (df.loc[row] == 0).any():
df.drop(row, axis=0, inplace=True)
return df
print('before')
print(df)
df = remove_any_zero_row(df)
print('after')
print(df)# Output
before
A B C
0 1 4 6
1 0 0 0
2 2 0 0
3 3 5 7
after
A B C
0 1 4 6
3 3 5 7
