Plotting multiple lines in one chart but next to each other using matplotlib

Question

I have the following quarterly df.

group date          share
A     2018-03-31    0.03
A     2018-06-30    0.03
A     2018-09-30    0.03
A     2018-12-31    0.02
A     2019-03-31    0.02
B     2018-03-31    0.04
B     2018-06-30    0.04
B     2018-09-30    0.05
B     2018-12-31    0.06
B     2019-03-31    0.07
C     2018-03-31    0.05
C     2018-06-30    0.06
C     2018-09-30    0.07
C     2018-12-31    0.07
C     2019-03-31    0.09

UPDATE

i used the code suggested below

fig,ax=plt.subplots(figsize=(10,6))
df.set_index(['group'], append=True).unstack()['share'].plot(ax=ax)
ax.set(xticks=np.arange(0,len(df)))
plt.legend(loc='upper left')
ax.set_xticklabels(df.date.dt.to_period('Y').astype(str).values, rotation = 45)
ax.grid(which='major', alpha=0.5)
ax.grid(which='minor', alpha=0.2)
plt.ylim(0, 0.22)
plt.show()

I have this overlapping x-axis ticks. How can i only have the start and the end year for each group?

Answer 1

As your dates are repeating but you do not want the lines on top of one another, you will need to plot the data as you have done above and then change the tick labels so that the dates show up. See if this is what you are looking for... Note that I have plotted with the limited data you have provided.

fig,ax=plt.subplots(figsize=(10,6))
df.set_index('group', append=True).unstack()['share'].plot(ax=ax)
ax.set(xticks=np.arange(0,len(df)))
ax.set_xticklabels(df.date.astype(str).values, rotation = 45)
ax.grid(None)