Why are my subplots plotting only to the last ax?

Question

So in Spyder IPython and in Jupyter notebook, the following code is failing to create subplots:

import numpy as np
import pandas as pd
import matplotlib.pyplot as plt
mydict = {'a': [1,2,3,4], 'b':[2,3,4,5], 'c':[3,4,5,6]}
df = pd.DataFrame(mydict)
fig, axes = plt.subplots(3,1)
axes[0] = plt.plot(df.a)
axes[1] = plt.plot(df.b)
axes[2] = plt.plot(df.c)
plt.show(fig)

and it gives back the following plot:

this also happens when I copy-c copy-vd the example code from the matplotlib webpage

what I would like is the three columns in the three different subplots to be plotted

Answer 1

If you create your axes using plt.subplots you are using the object oriented approach in matplotlib. Then you have to call plot() on the axes object, so axes[0].plot(df.a), not plt.plot.

What you are doing is a weird hybrid between the procedural and object oriented approach and you also overwrite the axes objects that you created when you write axes[0] = plt.plot(....

import numpy as np
import pandas as pd
import matplotlib.pyplot as plt
mydict = {'a': [1,2,3,4], 'b':[2,3,4,5], 'c':[3,4,5,6]}
df = pd.DataFrame(mydict)
fig, axes = plt.subplots(3,1)
axes[0].plot(df.a)
axes[1].plot(df.b)
axes[2].plot(df.c)
plt.show()