Question

BANL16fd1c9a1:file_exceptions jjimmy$ python3 search_cofee_records.py
Please enter an item name:-Tea
Description will be :- Tea
QUANTITY will be :- 500
BANL16fd1c9a1:file_exceptions jjimmy$


BANL16fd1c9a1:file_exceptions jjimmy$ cat search_cofee_records_for.py
def main():

    infile=open('coffee.txt','r')
    search=input("Please enter an item :-")

    for line in infile:
        line=line.rstrip('\n')

        if (line==search):
            print("Description:-",line)

    infile.close()

main()

Answer 1

只需使用布尔标志：

stop = False
def main():

    infile = open('coffee.txt','r')
    search = input("Please enter an item :-")

    for line in infile:
        line=line.rstrip('\n')

        if stop:
            print(line)
            break  ## or stop = False if you want to keep on checking for more matches

        if (line==search):
            print("Description:-",line)
            stop = True

    infile.close()

基本上，我告诉python，找到匹配项后，我想在下一行停止，这就是为什么我使用stop标志，然后我break退出循环，以防止随后print行每一行。

Answer 2

我认为

 line=line.rstrip('\n')

应该在循环之前，并且应该将范围用于循环

def main():

    infile=open('coffee.txt','r')
    search=input("Please enter an item :-")
    lines=line.rstrip('\n')

    for i in range(len(lines)):

       if (lines[i]==search):
           print("Description:-",line)
           print(line[i+1])

    infile.close()

main()

Answer 3

这应该很好，除非您有一个不想加载到内存中的千兆字节文件（大多数作业没有这样的文件=）

def main():
    search=input("Please enter an item :-")

    with open('coffee.txt') as infile :
        data = [i.strip() for i in infile.readlines()]

    for a,b in zip(data,data[1:] :
        if a == search :
            print("Description:-", a)
            print("QUANTITY will be :-", b)   # the next line

main()

如何在python3中打印匹配字符串的下一行（如果我给Tea，它也应该打印下一行）

3 个答案: