您可以使用此代码

f = open("States and Capitals.txt","r")
x = input("enter value to search : ") 
searchlines = f.read()
if(searchlines.find(x)):
    print(x)
f.close()

我认为类似的方法可能有效。这样的结果是您将获得具有所需行的变量输出。然后可以打印出来。

rem

尝试一下。您可以先使用split()函数将文件输入拆分为一个列表，该函数在本例中使用"\n"或newline作为分隔符。然后，您只需从索引或找到的字符串（如果存在）中打印接下来的3行。在这里，我假设您要打印州，首府，鸟和花（总共4行）。

elif x == "2":
    f = open("States and Capitals.txt","r")
    x = input("Enter the state you would like to search: ") 
    searchlines = f.read().split("\n")
    if x in searchlines:
        index = searchlines.index(x)
        for i in range(4):
            print(searchlines[index+i])
    f.close()

如果您想从输出中排除状态，因为它可能是多余的，则可以进行以下较小更改：

elif x == "2":
    f = open("States and Capitals.txt","r")
    x = input("Enter the state you would like to search: ") 
    searchlines = f.read().split("\n")
    if x in searchlines:
        index = searchlines.index(x)
        for i in range(1,4):
            print(searchlines[index+i])
    f.close()

这是一种同时读取文件三行并从其发现匹配的状态（如果有）打印数据的方法：

from itertools import zip_longest

# See https://docs.python.org/3/library/itertools.html#itertools-recipes
def grouper(iterable,n,fillvalue=None):
    ''' Collect data into fixed-length chunks or blocks. '''
    # grouper('ABCDEFG',3,'x') --> ABC DEF Gxx"
    args = [iter(iterable)] * n
    return zip_longest(*args,fillvalue=fillvalue)


target_state = input('Please enter a state name: ')

with open('States and Capitals.txt','r') as file:
    for group in grouper(file,''):  # Read file three lines at a time.
        state,capital,bird = map(str.rstrip,group)  # Remove newlines.
        if state == target_state:
            print(f'State: {state},Bird: {bird}')
            break  # All done.
    else:
        print(f'Error: No state found named {target_state}')

示例输出：

State: Kansas,Bird: Western Meadowlark