IndexError: list index out of range when reading text file

Question

I'm trying to import data from .txt file in Python to draw them and when I want to run the program I get this error :

IndexError: list index out of range

This is a tutorial to draw some data from a file and the data as shown below:

0.,1.5
2.24425,1.5
4.48276,1.5
5.97701,1.5
7.47126,1.5
8.96552,1.5
11.204,1.5
13.4483,1.5
15.6925,1.5
16.4368,1.5
18.681,1.5
19.4253,1.5
20.75,1.48079
22.3958,1.45845
23.6551,1.42766
24.8608,1.36509
26.1056,1.28529
27.4468,1.21306
28.8132,1.16694
30.1137,1.08216
31.5696,984.851E-03
33.0455,903.886E-03
34.4998,834.626E-03
35.976,790.798E-03
37.5447,754.429E-03
38.9391,697.508E-03
40.6381,715.628E-03
42.5023,882.211E-03
44.4548,1.07169
46.4502,1.26281
47.9939,1.4163
49.4727,1.47307
50.9886 ,1.48932
52.4883,1.49803
53.9846,1.50005
55.4793,1.50108
56.9737,1.50113
58.4647,1.50104
59.9569,1.50067
61.4477,1.50024
62.941,1.49998
64.4312,1.49969
65.9247,1.49929
67.4158,1.49911
68.9096,1.49872
70.4016,1.4976
71.8958,1.49571
73.3918,1.49193
74.8895,1.48612
76.3943,1.4734
77.9068,1.45366
79.4224,1.39481
81.033,1.2964
82.7794,1.1667
84.4811,971.91E-03
86.4866,837.442E-03
88.0979,892.783E-03
89.4046,970.171E-03
90.8885,972.861E-03
92.3106,976.503E-03
93.7562,995.16E-03
95.2745,1.03632
96.7847,1.07072
98.2745,1.10487
99.7581,1.17663
101.079,1.24002
102.408,1.30343
103.686,1.36529
104.979,1.41119
106.239,1.45107
107.577,1.45885
109.25,1.47844
115.057,1.5
116.552,1.5
117.296,1.5
119.54,1.5
121.785,1.5
124.023,1.5
125.517,1.5
126.262,1.5
129.256,1.5
130.,1.5

This is my Python code below to import the file and draw it:

import matplotlib.pyplot as plt
import csv

x=[]
y=[]

with open('raneen.txt','r') as csvfile:
    plots=csv.reader(csvfile, delimiter=',')
    for row in plots:
        x.append(float(row[0])) 
        y.append(float(row[1]))
plt.plot(x,y,label='Loaded from file!')



plt.xlabel('x')
plt.ylabel('y')
plt.title('Interesting graph\nCheck it out')
plt.legend()

plt.show()

I expect a graph from this data in Python

Answer 1

Sicce没有,在你的数据文件中，你必须在csv.reader方法中指定delimiter参数：

plots=csv.reader(csvfile, delimiter='  ')

Answer 2

Before your edit the file was delimited with a variable length of spaces, like this

            0.                 1.5        
            2.24425            1.5        
            4.48276            1.5        
            5.97701            1.5        
            7.47126            1.5        
            8.96552            1.5        
           11.204              1.5        
           13.4483             1.5        
           15.6925             1.5        
           16.4368             1.5        
           18.681              1.5        
           19.4253             1.5        
           20.75               1.48079    
           22.3958             1.45845    
           23.6551             1.42766    
           24.8608             1.36509    
           26.1056             1.28529    
           27.4468             1.21306    
           28.8132             1.16694    
           30.1137             1.08216    
           31.5696           984.851E-03  
           33.0455           903.886E-03  
           34.4998           834.626E-03  
           35.976            790.798E-03  
           37.5447           754.429E-03  
           38.9391           697.508E-03  
           40.6381           715.628E-03  
           42.5023           882.211E-03  
           44.4548             1.07169    
           46.4502             1.26281    
           47.9939             1.4163     
           49.4727             1.47307    
           50.9886             1.48932    

So in order to get the two vectors, you can proceed like this:

x = []
y = []

with open(".../data.txt") as file:
    data = file.read()
data = data.split("\n")
for line in data:
    line = line.lstrip()
    x.append(float(line.split(" ")[0]))
    line = line.lstrip(line.split(" ")[0])
    y.append(float(line.strip()))

I know its not the most elegant approach and its sensitive to missing values, but for the supplied example it works