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

df.stack().reset_index(level=0, drop=True).sort_index()

Output:

NSW    6718023
NSW    6735528
NSW    6742690
NSW    6766133
NSW    6786160
VIC    5023203
VIC    5048207
VIC    5061266
VIC    5083593
VIC    5103965
dtype: int64