Pandas map string to int based on value in a column

You can use rank with cast to int:

df['label'] = df['total_sales'].rank(method='dense', ascending=False).astype(int)
print (df)
  state  total_sales  label
0    AL        16714      3
1    AR         6498      4
2    AZ       107296      1
3    CA        33717      2