Question

我试图定义这两个变量，然后在第6行再次使用它们。但是，运行时出现以下错误。这似乎只发生在pandas.date_range中。我的最终目标是将其作为.py文件运行以生成图表。

start_date = raw_input('enter start date: ')
end_date = raw_input('enter end date: ')

dataPR['date'] = pd.DatetimeIndex(dataPR['intake_date']).date
grouped_dataPR = dataPR.groupby(['date']).sum()
idx = pd.date_range(start='%s', end='%s') % (start_date, end_date)
grouped_dataPR.index = pd.DatetimeIndex(grouped_dataPR.index)
grouped_dataPR = grouped_dataPR.reindex(idx, fill_value=0)
grouped_dataPR['date'] = grouped_dataPR.index
dataPR_df = pd.DataFrame([grouped_dataPR])
ts = pd.Series(grouped_dataPR['count'], index=grouped_dataPR.index)
ts.plot()
pd.rolling_mean(ts,30).plot(style='k')

错误：

ValueError                                Traceback (most recent call            last)
<ipython-input-33-2ac5fe9d8951> in <module>()
  2 grouped_dataPR = dataPR.groupby(['date']).sum()
  3 #idx = pd.date_range('%s', '%s' % (start_date, end_date))
----> 4 idx = pd.date_range(start='%s', end='%s') % (start_date,     end_date)
      5 grouped_dataPR.index = pd.DatetimeIndex(grouped_dataPR.index)
      6 grouped_dataPR = grouped_dataPR.reindex(idx, fill_value=0)

/Users/abc/anaconda/lib/python2.7/site-    packages/pandas/tseries/index.pyc in date_range(start, end, periods,     freq, tz, normalize, name, closed, **kwargs)
   1921     return DatetimeIndex(start=start, end=end,     periods=periods,
   1922                          freq=freq, tz=tz,     normalize=normalize, name=name,
-> 1923                          closed=closed, **kwargs)
   1924 
   1925 

/Users/abc/anaconda/lib/python2.7/site-    packages/pandas/util/decorators.pyc in wrapper(*args, **kwargs)
     87                 else:
     88                     kwargs[new_arg_name] = new_arg_value
---> 89             return func(*args, **kwargs)
     90         return wrapper
     91     return _deprecate_kwarg

/Users/abc/anaconda/lib/python2.7/site-    packages/pandas/tseries/index.pyc in __new__(cls, data, freq, start, end,     periods, copy, name, tz, verify_integrity, normalize, closed, ambiguous,     dtype, **kwargs)
    235             return cls._generate(start, end, periods, name,     freq,
    236                                  tz=tz, normalize=normalize,     closed=closed,
--> 237                                  ambiguous=ambiguous)
    238 
    239         if not isinstance(data, (np.ndarray, Index,     ABCSeries)):

/Users/abc/anaconda/lib/python2.7/site-    packages/pandas/tseries/index.pyc in _generate(cls, start, end, periods,     name, offset, tz, normalize, ambiguous, closed)
    377 
    378         if start is not None:
--> 379             start = Timestamp(start)
    380 
    381         if end is not None:

pandas/tslib.pyx in pandas.tslib.Timestamp.__new__     (pandas/tslib.c:8973)()

pandas/tslib.pyx in pandas.tslib.convert_to_tsobject     (pandas/tslib.c:22522)()

pandas/tslib.pyx in pandas.tslib.convert_str_to_tsobject     (pandas/tslib.c:24520)()

ValueError:

Answer 1

您应该直接调用变量，而不用引号括起来。你试图以一种无趣的方式进行字符串替换。

idx = pd.date_range(start=start_date, end=end_date)

如果由于某种原因你仍然想要进行字符串替换，你必须这样做，单独替换每个字符串：

idx = pd.date_range(start='%s' % (start_date, ), end='%s' % (end_date, ))

Answer 2

我认为你只需要做

pandas.data_range

原因是start期望end和'%s'参数都有string or datetime-like个对象。 date_range不像日期时间那样。

如果这是一个有效的选项，那么你编写的代码试图在pandas pd.date_range(start='{}'.format(start_date), end='{}'.format(end_date))和一个字符串元组之间进行模运算，这很可能会引发其他错误。

如果您确实需要对这些值使用字符串格式，我建议使用新的字符串格式化方式，如

setmode(fileno(stdin), O_BINARY);

在string中调用变量返回ValueError

2 个答案: