comefrom: <qiyuangong>028_Implement_strStr()_2.py
code: def strStr( haystack, needle):
      lsh, lsn = len(haystack), len(needle)
      if lsn == 0:
          return 0
      pos, index = 0, 0
      while index <= lsh - lsn:
          if haystack[index] == needle[0]:
              
              if haystack[index:index + lsn] == needle:
                  return index
          index += 1
      return -1
masked: def sample_funcname ( var_0 , var_1 ) :
      var_3 , var_4 = len ( var_0 ) , len ( var_1 )
      if var_4 == 0 :
          return 0
      var_6 , var_7 = 0 , 0
      while var_7 <= var_3 - var_4 :
          if var_0 [ var_7 ] == var_1 [ 0 ] :
              if var_0 [ var_7 : var_7 + var_4 ] == var_1 :
                  return var_7
          var_7 += 1
      return - 1
  