大熊猫与Matplotlib开关轴

Question

（使用Python 3.5） 我有熊猫据帧表与colums：

Price| Quantity|Price| Quantity|Price|... 
2 | 1  |4 | 5  | 13 |... 

不是我画出这个

import matplotlib.pyplot as plt 
plt.plot(my_table, their_table) 
plt.show() 

它把价格X和数量Y上-轴。 我该如何切换，以便价格在Y轴上？

Answer 1

您可以使用lreshape与Series.plot：

print (df) 
    Price Quantity Price Quantity Price Quantity 
0  2   1  4   5  13  10 
1  8   7  2   3  6   8 

#remove duplicates in columns adding numbers 
L = ['Price', 'Quantity'] 
k = int(len(df.columns)/2) 
df.columns = ['{}{}'.format(x, y) for y in range(1, k+1) for x in L] 
print (df) 
    Price1 Quantity1 Price2 Quantity2 Price3 Quantity3 
0  2   1  4   5  13   10 
1  8   7  2   3  6   8 

#filter columns 
prices = [col for col in df.columns if col.startswith('Price')] 
quantities = [col for col in df.columns if col.startswith('Quantity')] 
print (prices) 
['Price1', 'Price2', 'Price3'] 

print (quantities) 
['Quantity1', 'Quantity2', 'Quantity3'] 

#reshape all values to 2 columns 
df = pd.lreshape(df, {'Price':prices, 'Quantity':quantities}) 
print (df) 
    Price Quantity 
0  2   1 
1  8   7 
2  4   5 
3  2   3 
4  13  10 
5  6   8 

df.set_index('Price')['Quantity'].plot()