我有以下熊猫DataFrame：
df
Date
2020-03-16 747.86
2020-03-13 761.78
2020-03-12 769.25
2020-03-11 811.35
2020-03-10 837.50
2000-08-07 106.92
2000-08-04 105.20
2000-08-02 103.38
2000-07-31 101.55
2000-07-28 100.00
Name: Close, Length: 4738, dtype: float64
当我过滤df['2014-12']时，我得到了真实的数据片段：
Date
2014-12-31 545.63
2014-12-30 537.57
2014-12-29 532.68
2014-12-26 533.37
2014-12-25 532.01
2014-12-24 539.44
2014-12-23 537.88
2014-12-22 537.54
2014-12-19 523.09
2014-12-18 528.45
2014-12-17 518.22
2014-12-16 535.14
2014-12-15 547.93
2014-12-12 553.93
2014-12-11 550.11
2014-12-10 557.19
2014-12-09 555.31
2014-12-08 571.68
2014-12-05 578.76
2014-12-04 578.38
2014-12-03 574.88
2014-12-02 569.43
2014-12-01 568.01
Name: Close, dtype: float64
但是当我想从期间获取数据时，会导致以下情况：
df['2014-12-01':'2014-12-05']
Series([], Name: Close, dtype: float64)
df.loc['2014-12-01':'2014-12-05']
Series([], Name: Close, dtype: float64)
您能帮我从上述期间中提取数据吗？
谢谢