名称 (?) 未定义

Question

我是 Python 编程的初学者 使用 PyCharm 尝试练习功能，但返回以下错误：

名称“rflag”未定义 但我认为它的定义！ 这是代码：

def searcher(word: str, text: str, num: int = 1):

   global startindex
   global size
   global rflag

   if num == 1 and text.count(word) == 1:
       startindex = text.find(word);
       size = len(word);
       rflag = "word start from " + str(startindex + 1) + " and end in " + 
       str(size + startindex)
   elif num > 1 and text.count(word) <= num:
       startindex = 0
       for i in range(num):
           startindex = text.find(word, startindex)
           size = startindex + len(word)
        rflag = "word start from " + str(startindex + 1) + " and end in " + 
        str(size + startindex)

    return rflag


result = searcher("shahab", "shahabshahabshahab", 2)
print(result)

完整的错误信息：

C:\Users\Shahab\AppData\Local\Programs\Python\Python37-32\python.exe C:/Users/Shahab/Desktop/searcher.py

Traceback（最近一次调用最后一次）：

文件“C:/Users/Shahab/Desktop/searcher.py”，第 21 行，在 result = searcher("shahab", "shahabshahabshahab", 2) 文件“C:/Users/Shahab/Desktop/searcher.py”，第 18 行，在搜索器中 return rflag NameError: name 'rflag' is not defined

进程以退出代码 1 结束

缩进： code and indentation image

Answer 1

这将解决错误。

您只需在 if 条件之前初始化 rflag，因为这就是您要返回的内容

def searcher(word, text, num=1):
  rflag = ""
  if num == 1 and text.count(word) == 1:
    startindex = text.find(word);
    size = len(word);
    rflag = "word start from {} and end in {}".format(startindex+1, size+startindex)
  elif num > 1 and text.count(word) <= num:
    startindex = 0
    for i in range(num):
      startindex = text.find(word, startindex)
      size = startindex + len(word)
      rflag = "word start from {} and end in {}".format(startindex+1, size+startindex)
  return rflag