CreateDate                Store       Orders_am        Orders_pm
0       2018-01-21                  2001           56               2
1       2018-01-21                  2002           51               4
2       2018-01-21                  2003           85               0

CreateDate        datetime64[ns]
Store             int64
Orders_am         int64
Orders_pm         int64

plt.plot(df.groupby("Store").plot(x="CreateDate", y="Orders_am"))

TypeError: float() argument must be a string or a number, not 'AxesSubplot'