import pandas as pd

# Creating a DataFrame
df = pd.DataFrame({'A': [1, 2, 3], 'B': [4, 5, 6], 'C': [7, 8, 9]})

# Drop one column and substitute the current data frame
df = df.drop('A', axis=1)

# Print updated data frame
print(df)

>>>

   B  C
0  4  7
1  5  8
2  6  9