Question

我有文件（字典），我想从文件中搜索特定内容，如何编写查询？

def name_search():
    target = open("customers.txt",'r')
    name_search = input('Search >')
    for line in target:
        if name_search in line:
            print(f'{name_search} in record!')
        else:
            print('Not in record!')

上面的代码有效，但是，它会尝试多次打印此行，具体取决于我在文件中有多少行。假设该行不存在：

Not in record!
Not in record!
Not in record!
Not in record!

Answer 1

如果您说您不想多次打印，只读完整个文件一次，那么请执行以下操作：

def name_search():
    target = open("customers.txt",'r')
    name_search = input('Search >')
    found = False  # use this to remember if we found something
    for line in target:
        if name_search in line:
            print(f'{name_search} in record!')
            found = True  # remember we found it!
            break  # this kicks you out of the loop, so you stop searching after you find something
    if not found:
        print('Not in record!')  # only prints this if we didn't find anything

或者，在更少的代码行中，您可以在＆＃34;找到＆＃34;中使用return语句。案件。人们有理由避免在代码中使用多个返回点，但我在此处将其作为选项提供：

def name_search():
    target = open("customers.txt",'r')
    name_search = input('Search >')
    for line in target:
        if name_search in line:
            print(f'{name_search} in record!')
            return  # kicks us out of the function after we find something
    print('Not in record!')  # still only prints this if we didn't find anything

从python中的文件字典中搜索内容

1 个答案: