Fix Python – Plot a bar using matplotlib using a dictionary


Asked By – otmezger

Is there any way to plot a bar plot using matplotlib using data directly from a dict?

My dict looks like this:

D = {u'Label1':26, u'Label2': 17, u'Label3':30}

I was expecting

fig = plt.figure(figsize=(5.5,3),dpi=300)
ax = fig.add_subplot(111)
bar =,range(1,len(D)+1,1),0.5)

to work, but it does not.

Here is the error:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python2.7/site-packages/matplotlib/", line 4904, in bar
  File "/usr/local/lib/python2.7/site-packages/matplotlib/", line 1570, in add_patch
  File "/usr/local/lib/python2.7/site-packages/matplotlib/", line 1588, in _update_patch_limits
    xys = patch.get_patch_transform().transform(vertices)
  File "/usr/local/lib/python2.7/site-packages/matplotlib/", line 580, in get_patch_transform
  File "/usr/local/lib/python2.7/site-packages/matplotlib/", line 576, in _update_patch_transform
    bbox = transforms.Bbox.from_bounds(x, y, width, height)
  File "/usr/local/lib/python2.7/site-packages/matplotlib/", line 786, in from_bounds
    return Bbox.from_extents(x0, y0, x0 + width, y0 + height)
TypeError: coercing to Unicode: need string or buffer, float found

Now we will see solution for issue: Plot a bar using matplotlib using a dictionary


You can do it in two lines by first plotting the bar chart and then setting the appropriate ticks:

import matplotlib.pyplot as plt

D = {u'Label1':26, u'Label2': 17, u'Label3':30}, list(D.values()), align='center')
plt.xticks(range(len(D)), list(D.keys()))
# # for python 2.x:
#, D.values(), align='center')  # python 2.x
# plt.xticks(range(len(D)), D.keys())  # in python 2.x

Note that the penultimate line should read plt.xticks(range(len(D)), list(D.keys())) in python3, because D.keys() returns a generator, which matplotlib cannot use directly.

This question is answered By – David Zwicker

This answer is collected from stackoverflow and reviewed by FixPython community admins, is licensed under cc by-sa 2.5 , cc by-sa 3.0 and cc by-sa 4.0