Matplotlib：無法將字符串轉換爲浮動

Question

我想從這個數據幀繪製信息：

         sold not_sold success_rate 
category PriceBucket PriceBucketTitle    
Papeterie 0    [0, 2]  42401 471886 17.130 
      1    (2, 3]  28627 360907 17.240 
      2    (3, 3.5] 46198 434063 18.370 
      3    (3.5, 4] 80307 564594 17.870 
      4    (4, 5]  28653 171226 16.860 
      5    (5, 6]  50301 415379 17.385 
      6    (6, 8]  45370 446013 17.730 
      7    (8, 10]  39859 360187 18.005 
      8    (10, 18] 52263 381596 17.630 
      9    (18, 585] 36897 387145 19.730 

這是我的代碼：

import matplotlib.pyplot as plt 
import numpy as np 

fig, ax = plt.subplots() 
plt.title('Success Rate By Category : ' + str(group['category'].iloc[0])) 
ax2 = ax.twinx() 

x = last_merge['PriceBucket'].as_matrix() 


ax2.bar(x, last_merge['sold'].as_matrix(), color='None') 
ax2.bar(x, last_merge['not_sold'].as_matrix(), color='None', edgecolor='red', hatch="/") 

ax.plot(x, last_merge['success_rate'].as_matrix(), color='blue') 

ax2.set_ylabel("Product's number", color='red') 
ax.set_ylabel(ylabel='Success Rate', color='blue') 

ax.set_xlabel('Same X-values') 
plt.show() 

現在我的目標是讓「PriceBucketTitle」在x上，而不是'PriceBucket'。錯誤消息：

ValueError: could not convert string to float: [0, 2] 

幫助？日Thnx

Answer 1

我這樣做：

fig, ax = plt.subplots() 
plt.title('Success Rate By Category') 
ax2 = ax.twinx() 

lmnew = last_merge.reset_index().set_index('PriceBucketTitle') 
lmnew.sold.plot.bar(color='None', ax=ax2) 
lmnew.not_sold.plot.bar(color='None', edgecolor='red', hatch='/', ax=ax2) 
lmnew.success_rate.plot(color='blue', ax=ax) 

ax2.set_ylabel("Product's number", color='red') 
ax.set_ylabel(ylabel='Success Rate', color='blue') 

ax.set_xlabel('Same X-values')