如何让python读取整个文本文件，而不仅仅是一行？

我一直试图让我的代码搜索用户输入的产品的文本文件，但它只读取第一行，而不是我想要的整个文件

这是我的密码：

 order=input("Please enter the name of the product you wish to purchase\n")
    myfile=open("barcode.txt","r")
    details=myfile.readlines() #reads the file and stores it as the variable 'details'
    for line in details:
        if order in line: #if the barcode is in the line it stores the line as 'productline'
            productline=line
            quantity=int(input("How much of the product do you wish to purchase?\n"))
            itemsplit=productline.split(' ') #seperates into different words
            price=float(itemsplit[1]) #the price is the second part of the line
            total=(price)*(quantity) #this works out the price
            print("Your total spent on this product is: " +'£'+str(total))
        else:
            break

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你正在打破这个循环： 顺便说一句，我添加了一个with statent，用于以更为python的方式打开文件

order = input("Please enter the name of the product you wish to purchase\n")
with open("barcode.txt","r") as myfile:
    details=myfile.readlines() #reads the file and stores it as the variable 'details'
    for line in details:
        if order in line: #if the barcode is in the line it stores the line as 'productline'
            productline=line
            quantity=int(input("How much of the product do you wish to purchase?\n"))
            itemsplit=productline.split(' ') #seperates into different words
            price=float(itemsplit[1]) #the price is the second part of the line
            total=(price)*(quantity) #this works out the price
            print("Your total spent on this product is: " +'£'+str(total))

您正在使用break过早退出循环：

for line in details:
        if order in line:
            # do stuff
        else:
            break  #<-- this is exiting the loop

或者您可以完全忽略其他内容：

for line in details:
        if order in line:
            # do stuff

---

您的代码将在选中1行后中断

你有

for line in details:
    if order in line:
        # Does stuff
    else:
        break
        # This breaks out of the `for line in details` loop.

因此，如果订单不在第一行，它将退出循环

你很可能正在寻找类似于

for line in details:
    if order in line:
        # Do stuff
        break # You want to break if you found the order
    else:
        continue

尽管在这种情况下，不需要else:continue分支，因为如果找不到订单，您不打算执行任何操作

另外，文件自然地支持迭代，所以您不需要执行以下操作

myfile = open("barcode.txt", "r")
details = myfile.readlines()
# this line ^ can be removed, and you can just iterate over the file object itself 
for line in myfile:
    # do stuff

完成后，不要忘记使用myfile.close关闭文件，或者使用类似的上下文管理器

with open("barcode.txt", "r") as myfile:
    for line in myfile:
        # Do stuff
# Once you go out of the `with` context, the file is closed for you

---

要读取文件，请检查：

几点建议：

一次获取所有输入。nt like QUOTE=INTINPUTH t的多少 一次读取所有数据。 一旦你得到了所有的变量，现在开始研究逻辑。 你不需要做productline=line 如果你不需要“else”，那么就不要使用它。

---

检查python的Zen、python PEP8、，还有一些编程标准和风格。让你的代码看起来很酷。

如果你在第一行中找不到顺序，你就会中断循环。你只得到一行的原因是因为你立即中断，用pass或suppress将其更改为else语句remove else：breakI认为continue可能更符合OP的预期虽然在这种情况下，当我运行代码时，同样是多余的，但我不断收到一条错误消息，说找不到barcode.txt。您是否在同一目录中创建了名为barcode.txt的文件？如果不是你需要创建它的话，我做的，可能只是我的电脑，它最近一直在播放。

with open("barcode.txt", "r") as myfile:
    for line in myfile:
        # Do stuff
# Once you go out of the `with` context, the file is closed for you

fp = open(file_name)
print fp.read() # prints all data in file name