我的python代碼有什麼問題？

Question

#!usr/bin/python 

listofnames = [] 

names = input("Pls enter how many of names:") 
x = 1 

for x in range(0, names): 
    inname = input("Enter the name " + str(x)) 
    listofnames.append(inname) 


print listofnames 

---

錯誤

inname = input("Enter the name " + str(x)) 

文件 「」，第1行，在 NameError：名稱 '約翰' 沒有定義

Answer 1

input從其隨後解釋爲Python的用戶得到的文本代碼（因此它試圖評估你輸入的東西，Jhon）。你需要raw_input他們兩個，你需要將輸入的數字（因爲它是一個字符串）轉換爲你的range的整數。

#!usr/bin/python 

listofnames = [] 
names = 0 
try: 
    names = int(raw_input("Pls enter how many of names:")) 
except: 
    print "Problem with input" 

for x in range(0, names): 
    inname = raw_input("Enter the name %d: "%(x)) 
    listofnames.append(inname) 

print listofnames 

Answer 2

改爲使用raw_input。見http://docs.python.org/library/functions.html#raw_input。 input將做與eval(raw_input(prompt))相同的事情，因此輸入Jhon將嘗試在文件內找到符號Jhon（不存在）。因此，對於您現有的腳本，您必須在提示中輸入'Jhon'（注意引號集），以便eval將該值轉換爲字符串。

以下是input文檔中的摘錄警告。

Warning

This function is not safe from user errors! It expects a valid Python expression as input; if the input is not syntactically valid, a SyntaxError will be raised. Other exceptions may be raised if there is an error during evaluation. (On the other hand, sometimes this is exactly what you need when writing a quick script for expert use.)

下面是修正版本：

#!usr/bin/python 

# The list is implied with the variable name, see my comment below. 
names = [] 

try: 
    # We need to convert the names input to an int using raw input. 
    # If a valid number is not entered a `ValueError` is raised, and 
    # we throw an exception. You may also want to consider renaming 
    # names to num_names. To be "names" sounds implies a list of 
    # names, not a number of names. 
    num_names = int(raw_input("Pls enter how many of names:")) 
except ValueError: 
    raise Exception('Please enter a valid number.') 

# You don't need x=1. If you want to start your name at 1 
# change the range to start at 1, and add 1 to the number of names. 
for x in range(1, num_names+1)): 
    inname = raw_input("Enter the name " + str(x)) 
    names.append(inname) 

print names 

注：這是Python2.x。正如其他答案中所解釋的，Python3.x修復了輸入與raw_input混淆的問題。

Answer 3

在python3中，input()現在可以像raw_input()一樣工作。然而，要讓你的代碼與Python3一起工作，仍然需要進行一些更改

#!usr/bin/python3 

listofnames = [] 

names = int(input("Pls enter how many of names:")) 
x = 1 

for x in range(0, names): 
    inname = input("Enter the name " + str(x)) 
    listofnames.append(inname) 


print(listofnames)