python pandas将索引转换为日期时间
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python pandas convert index to datetime
提问by Runner Bean
How do i convert a pandas index of strings to datetime format
我如何将字符串的熊猫索引转换为日期时间格式
my dataframe 'df' is like this
我的数据框“df”是这样的
value
2015-09-25 00:46 71.925000
2015-09-25 00:47 71.625000
2015-09-25 00:48 71.333333
2015-09-25 00:49 64.571429
2015-09-25 00:50 72.285714
but the index is of type string, but i need it a datetime format because i get the error
但索引是字符串类型，但我需要它的日期时间格式，因为我收到错误
'Index' object has no attribute 'hour'
when using
使用时
df['A'] = df.index.hour
回答by Romain
It should work as expected. Try to run the following example.
它应该按预期工作。尝试运行以下示例。
import pandas as pd
import io
data = """value
"2015-09-25 00:46" 71.925000
"2015-09-25 00:47" 71.625000
"2015-09-25 00:48" 71.333333
"2015-09-25 00:49" 64.571429
"2015-09-25 00:50" 72.285714"""
df = pd.read_table(io.StringIO(data), delim_whitespace=True)
# Converting the index as date
df.index = pd.to_datetime(df.index)
# Extracting hour & minute
df['A'] = df.index.hour
df['B'] = df.index.minute
df
# value A B
# 2015-09-25 00:46:00 71.925000 0 46
# 2015-09-25 00:47:00 71.625000 0 47
# 2015-09-25 00:48:00 71.333333 0 48
# 2015-09-25 00:49:00 64.571429 0 49
# 2015-09-25 00:50:00 72.285714 0 50
回答by blue_note
You could explicitly createa DatetimeIndexwhen initializing the dataframe. Assuming your data is in string format
您可以在初始化数据框时显式创建a DatetimeIndex。假设您的数据是字符串格式
data = [
('2015-09-25 00:46', '71.925000'),
('2015-09-25 00:47', '71.625000'),
('2015-09-25 00:48', '71.333333'),
('2015-09-25 00:49', '64.571429'),
('2015-09-25 00:50', '72.285714'),
]
index, values = zip(*data)
frame = pd.DataFrame({
'values': values
}, index=pd.DatetimeIndex(index))
print(frame.index.minute)
回答by Muhammad Ammar Fauzan
I just give other option for this question - you need to use '.dt' in your code:
我只是为这个问题提供了其他选项 - 您需要在代码中使用“.dt”：
import pandas as pd
df.index = pd.to_datetime(df.index)
#for get year
df.index.dt.year
#for get month
df.index.dt.month
#for get day
df.index.dt.day
#for get hour
df.index.dt.hour
#for get minute
df.index.dt.minute