ValueError：int（）與基數爲10的無效文字：''

Question

我必須從此代碼獲取圖形，但似乎有些東西不適用於它。

當我運行代碼，我得到這個：

ValueError: invalid literal for int() with base 10: '' 

這是代碼：

import matplotlib.pyplot as plt 

x=[] 
y=[] 

readFile = open("C:/Users/Martinez/Documents/Diego/Python/SampleData.txt","r") 

for linea in readFile: 
    print linea 

sepFile = readFile.read().split("\n") 
readFile.close() 

for plotPair in sepFile: 

    xAndY = plotPair.split(',') 
    x.append(int(xAndY[0])) 
    y.append(int(xAndY[1])) 


print x 
print y 

Answer 1

你的問題是，你正在閱讀的輸入文件中的每行第一個for linea in readFile環。當你試圖再次閱讀內容時，你只會得到一個空字符串。無論是消除了第一個for循環，或行sepFile = readFile.read().split("\n")

前加readFile.seek(0)程序的工作版本將

x = [] 
y = [] 
with open("C:/Users/Martinez/Documents/Diego/Python/SampleData.txt") as read_file: 
    for line in read_file: 
     print line 
     a, b = line.split(',') 
     x.append(int(a)) 
     y.append(int(b)) 

print x 
print y 

爲了說明問題遠一點：

>>> read_file = open('inp.txt') 
>>> for line in read_file: # reads entire contents of file 
...  print line 
... 
3,4 
5,6 
7,8 
9,10 
>>> read_file.read() # trying to read again gives an empty string 
'' 
>>> out = read_file.read() 
>>> int(out) # empty string cannot be converted to an int 
Traceback (most recent call last): 
    File "<stdin>", line 1, in <module> 
ValueError: invalid literal for int() with base 10: '' 

>>> read_file.seek(0) # moves to beginning of file 
>>> read_file.read() # now the content can be read again 
'3,4\n5,6\n7,8\n9,10\n'