Question

我的问题如下：

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"

比我添加以下代码：

else:
    print "Word not found"

但这显然无法奏效，因为它会打印出＃34; Word not found＆＃34;直到找到这个词。嗯..但是如何打印出找不到的单词？！我不知道。

提前谢谢！

Answer 1

Python有一个特殊的技巧：

else

此处for与break一致，如果循环正常完成而没有点击{{1}}，则专门执行。

Answer 2

如果您只想打印是否在任何一行中找到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

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")

作为奖励，这会记录文件中首次出现的字词，如果有的话。

Answer 4

如果您只需找到第一个匹配项，则可以在找到单词后立即返回函数。如果不需要

，这还有额外的好处，就是不必遍历整个文件

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"
        return 1
  print "Word not found"
  return 0

Answer 5

def searchWordlist():
    found_word = False
    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"
                found_word = True
    if not found_word:
        print "Word not found!"

这段代码的作用是它正常执行你的代码，除非它找到单词，它将布尔值设置为true，表示它已经找到了这个单词。然后，在完全解析文件之后，查看是否找到了该单词，如果该变量为真。如果找不到该单词，则会打印出未找到该单词的单词。如果您希望代码在首次找到该字词后停止，则break之后found_word = True会停止。

Python逐行检查列表

5 个答案: