https://praktikum.yandex.ru/trainer/data-analyst/lesson/cd601912-2c45-429c-b9f1-3ef16fb07a31/task/63e2c3f3-fa64-4376-8221-e8b753264535/
moscow_general = df[df['city'] == 'Moscow']
spb_general = df[df['city'] == 'Saint-Petersburg']
def genre_weekday(df, day, time1, time2):
    genre_list = df.loc[(df.loc['weekday'] == day) & (df['time'] > time1) & (df['time'] < time2)]
    genre_list_sorted = genre_list.groupby('genre_name')['genre_name'].count().sort_values(ascending = False).head(10) # в переменной genre_list_sorted сохраняются в порядке убывания
# первые 10 значений Series, полученной подсчётом числа значений 'genre_name'
# сгруппированной по столбцу 'genre_name' таблицы genre_list
    return genre_list_sorted
genre_weekday(moscow_general, 'Monday', '07:00:00', '11:00:00')

ошибка:
KeyError                                  Traceback (most recent call last)
/opt/conda/lib/python3.7/site-packages/pandas/core/indexes/base.py in get_loc(self, key, method, tolerance)
   2896             try:
-> 2897                 return self._engine.get_loc(key)
   2898             except KeyError:

pandas/_libs/index.pyx in pandas._libs.index.IndexEngine.get_loc()

pandas/_libs/index.pyx in pandas._libs.index.IndexEngine.get_loc()

pandas/_libs/index_class_helper.pxi in pandas._libs.index.Int64Engine._check_type()

KeyError: 'weekday'

During handling of the above exception, another exception occurred:

KeyError                                  Traceback (most recent call last)
<ipython-input-39-c72f8908eeff> in <module>
----> 1 genre_weekday(moscow_general, 'Monday', '07:00:00', '11:00:00')# <вызов функции для утра понедельника в Москве >

<ipython-input-38-e5cb073c083d> in genre_weekday(df, day, time1, time2)
      1 def genre_weekday(df, day, time1, time2):
----> 2     genre_list = df.loc[(df.loc['weekday'] == day) & (df['time'] > time1) & (df['time'] < time2)]
      3     genre_list_sorted = genre_list.groupby('genre_name')['genre_name'].count().sort_values(ascending = False).head(10) # в переменной genre_list_sorted сохраняются в порядке убывания
      4 # первые 10 значений Series, полученной подсчётом числа значений 'genre_name'
      5 # сгруппированной по столбцу 'genre_name' таблицы genre_list

/opt/conda/lib/python3.7/site-packages/pandas/core/indexing.py in __getitem__(self, key)
   1422
   1423             maybe_callable = com.apply_if_callable(key, self.obj)
-> 1424             return self._getitem_axis(maybe_callable, axis=axis)
   1425
   1426     def _is_scalar_access(self, key: Tuple):

/opt/conda/lib/python3.7/site-packages/pandas/core/indexing.py in _getitem_axis(self, key, axis)
   1848         # fall thru to straight lookup
   1849         self._validate_key(key, axis)
-> 1850         return self._get_label(key, axis=axis)
   1851
   1852

/opt/conda/lib/python3.7/site-packages/pandas/core/indexing.py in _get_label(self, label, axis)
    158             raise IndexingError("no slices here, handle elsewhere")
    159
--> 160         return self.obj._xs(label, axis=axis)
    161
    162     def _get_loc(self, key: int, axis: int):

/opt/conda/lib/python3.7/site-packages/pandas/core/generic.py in xs(self, key, axis, level, drop_level)
   3735             loc, new_index = self.index.get_loc_level(key, drop_level=drop_level)
   3736         else:
-> 3737             loc = self.index.get_loc(key)
   3738
   3739             if isinstance(loc, np.ndarray):

/opt/conda/lib/python3.7/site-packages/pandas/core/indexes/base.py in get_loc(self, key, method, tolerance)
   2897                 return self._engine.get_loc(key)
   2898             except KeyError:
-> 2899                 return self._engine.get_loc(self._maybe_cast_indexer(key))
   2900         indexer = self.get_indexer([key], method=method, tolerance=tolerance)
   2901         if indexer.ndim > 1 or indexer.size > 1:

pandas/_libs/index.pyx in pandas._libs.index.IndexEngine.get_loc()

pandas/_libs/index.pyx in pandas._libs.index.IndexEngine.get_loc()

pandas/_libs/index_class_helper.pxi in pandas._libs.index.Int64Engine._check_type()

KeyError: 'weekday'