matplotlib如何顯示軸值作爲字符串不是一個浮動範圍

Question

我寫了下面的腳本來繪製一個python列表中的項目的頻率。當列表是一個字符串，我不能夠在X軸顯示的實際字符串值，我得到這個錯誤：

Traceback (most recent call last): 
    File "testy.py", line 15, in <module> 
    plt.bar([row[0] for row in votes_count], [row[1] for row in votes_count]) 
    File "...\matplotlib\pyplot.py", line 2705, in bar 
    **kwargs) 
    File "....\matplotlib\__init__.py", line 1891, in inner 
    return func(ax, *args, **kwargs) 
    File "....\matplotlib\axes\_axes.py", line 2105, in bar 
    left = [left[i] - width[i]/2. for i in xrange(len(left))] 
TypeError: unsupported operand type(s) for -: 'str' and 'float' 

下面是代碼：

from collections import Counter 
import matplotlib.pyplot as plt 
import plotly.plotly as py #pip install plotly 

votes = ['a','a','b','c','d'] 
tmp_votes_count = Counter (votes) 
votes_count = [] 

for i in tmp_votes_count: 
    votes_count.append ([i, tmp_votes_count[i]]) 


margin = 2 
most_common_vote= [item for item in Counter(votes).most_common(1)] 
plt.bar([row[0] for row in votes_count], [row[1] for row in votes_count]) 
plt.axis([0,4,0,most_common_vote[0][1]+margin]) 
plt.show() 

Answer 1

您首先需要限定軸線作爲整數

plt.bar(range(0, len(votes_count)), [row[1] for row in votes_count]) 

，然後將它們映射到實際str對象

plt.xticks(range(0, len(votes_count)), [row[0] for row in votes_count]) 

最後，3個最後重構行：

plt.bar(range(0, len(votes_count)), [row[1] for row in votes_count]) 
plt.xticks(range(0, len(votes_count)), [row[0] for row in votes_count]) 
plt.show() 

輸出：