Pandas plot doesn't show

Once you have made your plot, you need to tell matplotlib to show it. The usual way to do things is to import matplotlib.pyplot and call show from there:

import numpy as np
import pandas as pd
import matplotlib.pyplot as plt
ts = pd.Series(np.random.randn(1000), index=pd.date_range('1/1/2000', periods=1000))
ts.plot()
plt.show()

Since you have requested not to do that (why?), you could use the following [NOTE: This no longer appears to work with newer versions of pandas]:

import numpy as np
import pandas as pd
ts = pd.Series(np.random.randn(1000), index=pd.date_range('1/1/2000', periods=1000))
ts.plot()
pd.tseries.plotting.pylab.show()

But all you are doing there is finding somewhere that matplotlib has been imported in pandas, and calling the same show function from there.

Are you trying to avoid calling matplotlib in an effort to speed things up? If so then you are really not speeding anything up, since pandas already imports pyplot:

python -mtimeit -s 'import pandas as pd'
100000000 loops, best of 3: 0.0122 usec per loop

python -mtimeit -s 'import pandas as pd; import matplotlib.pyplot as plt'
100000000 loops, best of 3: 0.0125 usec per loop

Finally, the reason the example you linked in comments doesn't need the call to matplotlib is because it is being run interactively in an iPython notebook, not in a script.

In case you are using matplotlib, and still, things don't show up in iPython notebook (or Jupyter Lab as well) remember to set the inline option for matplotlib in the notebook.

import matplotlib.pyplot as plt

%matplotlib inline

Then the following code will work flawlessly:

fig, ax = plt.subplots(figsize=(16,9));
change_per_ins.plot(ax=ax, kind='hist')

If you don't set the inline option it won't show up and by adding a plt.show() in the end you will get duplicate outputs.