林的Python检查表行

Question

我的问题是：

def searchWordlist():
path = str(raw_input(PATH))
word = str(raw_input(WORD))
with open(path) as f:
    for line in f:
        if word in line:
            print "Word found"

然后我添加了以下代码：

else:
    print "Word not found"

但这显然是行不通的，因为在找到单词之前，它会打印“wordnotfound”。好。。但我怎么能打印出找不到这个词？！我真的不知道。你知道吗

提前谢谢！你知道吗

Answer 1

def searchWordlist():    
    path = str(raw_input(PATH))
    word = str(raw_input(WORD))
    loc = -1
    with open(path) as f:
        for i, line in enumerate(f):
            if word in line:
                loc = i
                break
    if loc >= 0:
        print ("Word found at line {}".format(loc))
    else:
        print ("Word not found")

作为一个额外的好处，它可以跟踪单词在文件中的第一个出现位置（如果有的话）。你知道吗

Answer 2

如果您只想打印是否在任何行中找到word：

def searchWordlist():    
    path = str(raw_input(PATH))
    word = str(raw_input(WORD))
    with open(path) as f:
        if any(word in line for line in f):
            print('Word found')
        else:
            print('Word not found')

Answer 3

Python有一个特殊的技巧：

for line in f:
    if word in line:
        print "Word found"
        break
else:
    print "Word not found"

这里的else与for一起使用，如果循环正常完成而未命中break，则具体执行。你知道吗