Python while 循环迭代不起作用

Question

我是 Python 编程的新手，几个小时都无法解决以下问题。我有包含四行的示例文件。我希望在文件行中找到用户输入时获得两个输入，但是我的循环似乎没有遍历所有 lines.This 是文件的内容，元素由 [=25 分隔=]：

Google 1 2  
Apple 13 17  
Microsoft 22 8  
Verizon 6 15

这是我的代码：

import sys
with open('manylines.txt','r') as myfile:
    results = [line.split() for line in myfile]

    for i in results:
        print(i)


        term1=input("Enter the first term:")
        while  term1 not in i :
            print("Term not found,please try again:")
            term1 = input("Enter the first term:")

        term2 = input("Enter the second term:")
        while term2 not in (i) :
            print("Term not found,please try again:")
            term2 = input("Enter the second term:")
        print(i)
        print(i)
        sys.exit()

我希望输入 Google 和 Microsoft 并获得以下输出：

['Google','1','2']  
['Microsoft','22','8']

作为两个列表。但是，我的代码只找到第一行而不是其他行。你能告诉我为什么它不遍历其他行吗？如何解决这个问题？提前致谢！

Answer 1

这里有一些东西不会改变你尝试的代码......它利用 lower() and title() 来允许用户输入的各种大写：

import sys

with open('data.txt','r') as f:
    results = [line.split() for line in f]

while True:
    found = False
    term = input("Enter a company to search or type exit: ")
    if term.lower() == "exit":
        break
    for record in results:
        if record[0] == term.title():
            print(record)
            found = True
            break
    if not found:
        print("Term not found, please try again...")

print("Goodbye!")
sys.exit(0)

用法示例：

Enter a company to search or type exit: Google
['Google', '1', '2']
Enter a company to search or type exit: microsoft
['Microsoft', '22', '8']
Enter a company to search or type exit: Amazon
Term not found, please try again...
Enter a company to search or type exit: Exit
Goodbye!

这里是如何只提示用户只输入 "two terms":

out1, out2 = [], []
term_count = 1
while term_count < 3:
    found = False
    term = input("Enter term %d or type exit: " % term_count)
    if term.lower() == "exit":
        break
    for record in results:
        if term_count == 1 and record[0] == term.title():
            print(record)
            out1 = list(record)
            found = True
            term_count += 1
            break
        if term_count == 2 and record[0] == term.title():
            print(record)
            out2 = list(record)
            found = True
            term_count += 1
            break
    if not found:
        print("Term not found, please try again...")

用法示例：

Enter term 1 or type exit: Amazon
Term not found, please try again...
Enter term 1 or type exit: Google
['Google', '1', '2']
Enter term 2 or type exit: Microsoft
['Microsoft', '22', '8']
Goodbye!

Answer 2

试试下面的代码。此代码标识找到的术语并询问未找到的术语。

你没有正确地循环。当您的循环第一次执行时，它有 Google 并且 term1 包含 Google 并且 term2 包含 Microsoft。所以它打印 Google 之后你使用 sys.exit() 停止执行。所以它当然会打印第一行而不是其他行。

import sys
with open('tempa.txt','r') as myfile:
    results = [line.split() for line in myfile]

NeedToExecute = 0
term1 = False
term2 = False

list1 = None
list2 = None

while NeedToExecute != 2:

    if(term1 != True):
        term1 = input("Enter the first term:")

    if(term2 != True):
        term2 = input("Enter the second term:")

    for i in results:

        if term1 in i :
            NeedToExecute = NeedToExecute + 1
            term1 = True
            list1 = i
            print(i)

        if term2 in i :
            NeedToExecute = NeedToExecute + 1
            term2 = True
            list2 = i
            print(i)

print list1
print list2

Python while 循环迭代不起作用

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