[英]Conversion python dataframe character column to r with rpy2
I am trying to convert a python dataframe to r with rpy2 and I cannot get a date in python dataframe to be converted to a date type in r dataframes. I am trying to convert a python dataframe to r with rpy2 and I cannot get a date in python dataframe to be converted to a date type in r dataframes.
When converting a pd.to_datetime()
to r dataframe I am not getting a correct conversion.将pd.to_datetime()
转换为 r dataframe 时,我没有得到正确的转换。
df date columns in question: df 日期列有问题:
event_time
0 2019-10-11
1 2020-01-01
2 2019-11-15
3 2020-03-05
Conversion code:转换代码:
with localconverter(ro.default_converter + pandas2ri.converter):
df['event_time'] = pd.to_datetime(df['event_time']).dt.strftime("%Y-%m-%d")
df["event_time"] = pd.to_datetime(df["event_time"]).dt.date
r_df = ro.conversion.py2rpy(df)
Produces:产生:
event_time: <class 'numpy.ndarray'>
array([737343., 737425., 737378., 737489.])
And the same thing for discharge_time.放电时间也是如此。
Conversion code with string and then attempt to convert:用字符串转换代码,然后尝试转换:
with localconverter(ro.default_converter + pandas2ri.converter):
df['event_time'] = pd.to_datetime(df['event_time']).dt.strftime("%Y-%m-%d")
#### df["event_time"] = pd.to_datetime(df["event_time"]).dt.date
r_df = ro.conversion.py2rpy(df)
r_df = base.cbind(r_df, event_time = base.as_Date(r_df[r_df.names.index('event_time')], '%Y-%m-%d'))
Produces a dataframe with:产生一个 dataframe :
event_time: <class 'numpy.ndarray'>
array(['2019-10-11', '2020-01-01', '2019-11-15', '2020-03-05'], dtype='<U10')
But this line of code r_df = base.cbind(r_df, event_time = base.as_Date(r_df[r_df.names.index('event_time')], '%Y-%m-%d'))
errors with:但是这行代码r_df = base.cbind(r_df, event_time = base.as_Date(r_df[r_df.names.index('event_time')], '%Y-%m-%d'))
错误:
AttributeError: 'numpy.ndarray' object has no attribute 'index' AttributeError: 'numpy.ndarray' object 没有属性 'index'
Using this code produces:使用此代码会产生:
with localconverter(ro.default_converter + pandas2ri.converter):
df['event_time'] = pd.to_datetime(df['event_time']).dt.strftime("%Y-%m-%d")
#### df["event_time"] = pd.to_datetime(df["event_time"]).dt.date
r_df = ro.conversion.py2rpy(df)
r_df = base.cbind(r_df, event_time = base.as_Date(r_df[r_df.rx2('event_time')], '%Y-%m-%d'))
Error:错误:
Conversion 'py2rpy' not defined for objects of type '<class 'numpy.ndarray'>'未为“<class 'numpy.ndarray'>”类型的对象定义转换“py2rpy”
So how do I get a date from a python dataframe into a date in r with rpy2?那么如何使用 rpy2 从 python dataframe 中获取日期到 r 中的日期? I need it in a date format because I will be doing date calculations later on and strings will not work.我需要日期格式,因为稍后我将进行日期计算,而字符串将不起作用。
Versions:版本:
pandas==1.0.1熊猫==1.0.1
rpy2~=3.3.5 rpy2~=3.3.5
Your problem has nothing to do with rpy2, you are just parsing dates incorrectly in pandas.您的问题与 rpy2 无关,您只是在 pandas 中错误地解析日期。 See:看:
from pandas import DataFrame, to_datetime
df = DataFrame(dict(event_time=['2019-10-11', '2020-01-01']))
df.event_time = to_datetime(df.event_time)
print(list(df.event_time))
# [Timestamp('2019-10-11 00:00:00'), Timestamp('2020-01-01 00:00:00')]
# you using dt.strftime you was just converting them back to strings, see:
print(list(df.event_time.dt.strftime("%Y-%m-%d")))
# ['2019-10-11', '2020-01-01', '2019-11-15']
# now you could extract date object (but don't! timestamps are fine for rpy2)
print(list(df.event_time.dt.date))
# [datetime.date(2019, 10, 11), datetime.date(2020, 1, 1)]
Now in rpy2 you simply do:现在在 rpy2 中,您只需执行以下操作:
from rpy2.robjects import conversion, default_converter, pandas2ri
from rpy2.robjects.conversion import localconverter
with localconverter(default_converter + pandas2ri.converter):
df_r = conversion.py2rpy(df)
print(repr(df_r.rx2('event_time')))
# R object with classes: ('POSIXct', 'POSIXt') mapped to:
# [2019-10-11, 2020-01-01]
Now you can have fun with handling the dates on the R side, see dates .现在,您可以在 R 方面享受处理日期的乐趣,请参阅dates 。 Also, if you happen to use Jupyter notebooks, conversion is much more handy using cell magics .此外,如果您碰巧使用 Jupyter 笔记本,使用cell magics进行转换会更方便。
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