AttributeError Traceback (most recent call last) Cell In[27], line 5 1 from statsmodels.graphics.tsaplots import month_plot 3 fig,ax = plt.subplots(figsize=(22,8)) ----> 5 month_plot(data,ylabel='Rose',ax=ax) 6 plt.grid() File ~\anaconda3\Lib\site-packages\statsmodels\graphics\tsaplots.py:462, in month_plot(x, dates, ylabel, ax) 459 if dates is None: 460 from statsmodels.tools.data import _check_period_index --> 462 _check_period_index(x, freq="M") 463 else: 464 x = pd.Series(x, index=pd.PeriodIndex(dates, freq="M")) File ~\anaconda3\Lib\site-packages\statsmodels\tools\data.py:17, in _check_period_index(x, freq) 15 else: 16 inferred_freq = pd.infer_freq(x.index) ---> 17 if not inferred_freq.startswith(freq): 18 raise ValueError("Expected frequency {}. Got {}".format(inferred_freq, 19 freq)) AttributeError: 'NoneType' object has no attribute 'startswith