如何在pandas中删除datetime变量之前的行？

当我尝试在给定日期时间之前选择和删除行时，我的代码返回一个完全空的数据帧。以字符串形式传递日期时间是可行的，但是我需要它是一个基于dataframe的最后一个日期时间值的变量

In:
df_transposed['Interval_Date'] = pd.to_datetime(df_transposed['Interval_Date'])
filter_range_begin = str((datetime.now() - timedelta(hours=2)).strftime("%Y-%m-%d %H:%M:%S"))
df_transposed = df_transposed.set_index('Interval_Date')
indexNames = df_transposed[df_transposed.index.get_level_values(0) > filter_range_begin]

Out:
Empty DataFrame
Columns: [0, 1, Label]
Index: []

鉴于：

In:
df_transposed['Interval_Date'] = pd.to_datetime(df_transposed['Interval_Date'])
filter_range_begin = '2020-09-01 02:00:00'
df_transposed = df_transposed.set_index('Interval_Date')
indexNames = df_transposed[df_transposed.index.get_level_values(0) > filter_range_begin]

返回：

Out:
                         0    1  Label
Interval_Date                          
2020-09-01 02:15:00  401121  NaN    NaN
2020-09-01 02:30:00  815314  NaN    NaN
2020-09-01 02:45:00  885369  NaN    NaN

我还需要删除任何超出此范围的行

多谢各位

import pandas
from datetime import datetime

df_transposed = df_transposed[df_transposed['Interval_Date'] < datetime.strptime(df_transposed['Interval_Date'].min(),'%Y-%m-%d')]

#You can put the date directly instead of df_transposed['Interval_Date'].min()