Using dictionary to make a matplotlib graph?

Question

If I had a dictionary of words and their frequency in a string, for example:

{'hello': 3, 'how': 4, 'yes': 10, 'you': 11, 'days': 10, 'are': 20, 'ago': 11}

How could I make a bar graph out of this using matplotlib? I found a previous question which had a seemingly good solution, but it didn't work for me (python: plot a bar using matplotlib using a dictionary)

When I run

plt.bar(range(len(d)), d.values(), align="center")
plt.xticks(range(len(d)), d.keys())

I get the error

TypeError: 'dict_keys' object does not support indexing

I don't really see where I'm indexing my dictionary. It might be because in the question from which I got the code the x-values were also numbers? I'm not sure.

score 10 · Accepted Answer · answered Feb 21 '14 at 04:02

10

Try wrapping your d.keys() in a list() call:

plt.bar(range(len(d)), d.values(), align="center")
plt.xticks(range(len(d)), list(d.keys()))

In Python3, dict.keys() doesn't return the list of keys directly, but instead returns a generator that will give you the keys one at a time as you use it.

answered Feb 21 '14 at 04:02

Marius

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Worked perfectly, thank you! I'll keep in mind that's how dict.keys() works. – Howcan Feb 21 '14 at 04:10
This isn't very relevant to my question, but is there any way I can automate the space between the bars so that all the words can fit on the x-axis (or maybe make the words go to a new line?) – Howcan Feb 21 '14 at 04:12
@Howcan maybe you'd like to split the long words to multiple lines? – zhangxaochen Feb 21 '14 at 04:31

zhangxaochen · Answer 2 · 2014-02-22T07:06:37.947

On " is there any way I can automate the space between the bars so that all the words can fit on the x-axis (or maybe make the words go to a new line?)"

I will split the long words to multiple lines, e.g., 'looooooooongWord' to 'looooo-\noooong-\nWord':

In [300]: d={'hello': 3, 'how': 4, 'yes': 10, 'you': 11, 'days': 10, 'are': 20, 'ago': 11, 'looooooooongWord': 10}
     ...: plt.bar(range(len(d)), d.values(), align="center")
     ...: plt.xticks(range(len(d)), [split_word(i) for i in d.keys()])

where split_word is defined as:

In [595]: def split_word(s):
     ...:     n=6
     ...:     return '-\n'.join(s[i:i+n] for i in range(0, len(s), n))
     ...: split_word('looooooooongWord')
Out[595]: 'looooo-\noooong-\nWord'

enter image description here

Using dictionary to make a matplotlib graph?

2 Answers2