如何使用matplotlib在没有overlapp的情况下调整月份？

Question

I'm trying to plot the following data with matplotlib.

      Month    A     B       C
0   2014/06    41    17      3
1   2014/07    48    11      7
2   2014/08    58    20      4
3   2014/09    43    16      6
4   2014/10    73    13      7
5   2014/11    69    22     16
6   2014/12    65    34      9
7   2015/01    69    27     12

I'm having the following code:

x = np.arange(len(df["Month"].values))
y1=df["A"].values.astype(int)
y2=df["B"].values.astype(int)
y3=df["C"].values.astype(int)

my_xticks = df["Month"].values
plt.xticks(x, my_xticks)
plt.plot(x,y1)
plt.plot(x,y2)
plt.plot(x,y3)
plt.show()

The problem is the months are overlapping each other on x-axis. Can I make this automatically adjusted by Python. Not only I need to rotate, but also automatically ignore some months. Otherwise, it's too crowded.

Answer 1

Matplotlib has a function which can automatically format your x axis when they are dates - autofmt_xdate . This automatically rotates the labels, and positions the ticks. They can be changed from the defaults by passing arguments to this function. They can also, of course, be changed manually, but this requires (slightly) more effort.

You can easily reduce the number of dates shown be sampling every 2nd element of the list, using the slice notation [::2]

# Code here that creates a list of dates called list_of_dates...
print (list_of_dates)
# ['2016-08', '2016-09', '2016-10', '2016-11', '2016-12', '2017-01',
# '2017-02', '2017-03', '2017-04', '2017-05', '2017-06', '2017-07',
# '2017-08', '2017-09', '2017-10', '2017-11', '2017-12', '2018-01']
x = np.arange(0, len(list_of_dates), 1)

plt.xticks(x[::2], list_of_dates[::2])
plt.plot(x, np.random.randn(len(list_of_dates)))

# plt.gcf() means "get current figure"
plt.gcf().autofmt_xdate(ha="center")

plt.show()

Which gives: