Melting a pandas dataframe

Question

I have a dataframe like this

    NSW     VIC
0   6718023 5023203
1   6735528 5048207
2   6742690 5061266
3   6766133 5083593
4   6786160 5103965

Answer 1

Using df.unstack

df = df.unstack().to_frame().reset_index(level=0).iloc[:, [-1, 0]]
df.columns = [0, 1]   # or whatever else you please
df

         0    1
0  6718023  NSW
1  6735528  NSW
2  6742690  NSW
3  6766133  NSW
4  6786160  NSW
0  5023203  VIC
1  5048207  VIC
2  5061266  VIC
3  5083593  VIC
4  5103965  VIC