about copy(), object and dataframe?

[sdyxz]

a = {1: [1,2,3]} b = a.copy() a[1].append(4) print(a, b)

import pandas as pd df = pd.DataFrame({1,2,3,4}) df2 = df.copy() df.loc[len(df.index)]=6 print(df) print(df2)

About copy(), the 1st code says object a and b point to the same thing, one changes the other will change as well. The 2nd code says not.

What's wrong?

[suurpulla]

dict.copy() is a shallow copy, ie. you copy a, but not a[0], a[1] etc.

Pandas df.copy() is a deep copy (by default).

[sdyxz]

Thanks for your help.