python 新建一列_在dataframe中创建一个新列,该列基于另一列递增
考虑以下pandas数据帧:from pandas import Timestampdf = pd.DataFrame({'day': [Timestamp('2017-03-27'),Timestamp('2017-03-27'),Timestamp('2017-04-01'),Timestamp('2017-04-03'),Timestamp('2017-04-06'),Timestamp('...