我正在使用Pandas 0.19.
考虑以下数据框:
FID admin0 admin1 admin2 windspeed population
0 cntry1 state1 city1 60km/h 700
1 cntry1 state1 city1 90km/h 210
2 cntry1 state1 city2 60km/h 100
3 cntry1 state2 city3 60km/h 70
4 cntry1 state2 city4 60km/h 180
5 cntry1 state2 city4 90km/h 370
6 cntry2 state3 city5 60km/h 890
7 cntry2 state3 city6 60km/h 120
8 cntry2 state3 city6 90km/h 420
9 cntry2 state3 city6 120km/h 360
10 cntry2 state4 city7 60km/h 740
我怎样才能创建这样一个表？
population
60km/h 90km/h 120km/h …