Good day. Why does Python say that the function is not defined?

main.py:

class Parser: acc = 0.0 rest = '' def parse(self, s): self.acc = 0.0 self.rest = s parse_plusminus() return self.acc def parse_plusminus(self): cur = parse_num() while len(self.rest) > 0: if not (self.rest[0] == '+' or self.rest[0] == '-'): break sign = self.rest[0] next_num = parse_num(self.rest[1:]) if sign == '+': self.acc += cur + next_num else: self.acc += cur - next_num def parse_num(self): negative = False i = 0 if self.rest[0] == '-': negative = True self.rest = self.rest[1:] while i < len(self.rest) and (self.rest[i].isdigit() or self.rest[i] == '.'): i += 1 num = -float(self.rest[0:i]) if negative else float(self.rest[0:i]) self.rest = self.rest[i:] return num p = Parser() print(p.parse("1+2"))

  • Not a python connoisseur, but isn't it necessary to put this or self when calling a class method? - user207618
  • I'm also not an expert, the second time I write something .. Most likely you are right. - nrdgrauf
  • one
    Then it is better to start with textbooks and examples than to write at random. - user207618 pm

1 answer 1

 class Parser: acc = 0.0 rest = '' def parse(self, s): self.acc = 0.0 self.rest = s self.parse_plusminus() # Add self return self.acc def parse_plusminus(self): cur = self.parse_num() # Add self while len(self.rest) > 0: if not (self.rest[0] == '+' or self.rest[0] == '-'): break sign = self.rest[0] self.rest = self.rest[1:] # Remove first char? I guess so next_num = self.parse_num() # Add self if sign == '+': self.acc += cur + next_num else: self.acc += cur - next_num def parse_num(self): negative = False i = 0 if self.rest[0] == '-': negative = True self.rest = self.rest[1:] while i < len(self.rest) and (self.rest[i].isdigit() or self.rest[i] == '.'): i += 1 num = -float(self.rest[0:i]) if negative else float(self.rest[0:i]) self.rest = self.rest[i:] return num p = Parser() print(p.parse("1+3")) # Output: 4.0