Function name is not defined in a Python class

Question

I have written a class like below:

class Logger:

    @staticmethod
    def get_timestamp():
        import datetime
        return datetime.datetime.utcnow()
    
    def print_log(self,color, write_level, msg):
        return color

    def log_level_print(self,log_level, write_level, msg):
        if log_level == 'ERROR':
            return print_log(bcolors.FAIL, write_level, msg)
        if log_level == 'WARN':
            return print_log(bcolors.WARNING, write_level, msg)
        if log_level == 'INFO':
            return print_log(bcolors.OKGREEN, write_level, msg)
        if log_level == 'DEBUG':
            return print_log(bcolors.OKBLUE, write_level, msg)
        else:
            print(f"{Logger.get_timestamp()} {bcolors.FAIL}: Invalid LOG type{bcolors.ENDC}")
            return

Here, I am using this class :

from logger import Logger
demo = Logger()
print(demo.log_level_print('ERROR','ssdsd','sdsdsd'))

I am not able to call this function, I'm getting an error:
NameError: name 'print_log' is not defined

You forgot the `self` as first argument in the definition of `log_level_print`... (same goes for `print_log` by the way) — Tomerikoo, Sep 17 '20 at 11:49
The first argument should be `self`, change it to `log_level_print(self, log_level, write_level, msg`). — bertdida, Sep 17 '20 at 11:49
Does this answer your question? [TypeError: method() takes 1 positional argument but 2 were given](https://stackoverflow.com/questions/23944657/typeerror-method-takes-1-positional-argument-but-2-were-given) — Tomerikoo, Sep 17 '20 at 11:51

score 5 · Accepted Answer · edited Sep 17 '20 at 14:16

You forgot to add self as the first argument of class' methods and when you use the methods. Corrected code:

class Logger:
    @staticmethod
    def get_timestamp():
        import datetime
        return datetime.datetime.utcnow()

    def print_log(self, color, write_level, msg):
        return color

    def log_level_print(self, log_level, write_level, msg):
        if log_level == 'ERROR':
            return self.print_log(bcolors.FAIL, write_level, msg)
        if log_level == 'WARN':
            return self.print_log(bcolors.WARNING, write_level, msg)
        if log_level == 'INFO':
            return self.print_log(bcolors.OKGREEN, write_level, msg)
        if log_level == 'DEBUG':
            return self.print_log(bcolors.OKBLUE, write_level, msg)
        else:
            print(f"{Logger.get_timestamp()} {bcolors.FAIL}: Invalid LOG type{bcolors.ENDC}")
            return

Look, it's a code I'm running:

demo = Logger()
print(demo.log_level_print('ERROR','ssdsd','sdsdsd'))

and this is a result:

I'm running this code (without `bcolors`) and there is no error. — maciejwww, Sep 17 '20 at 12:12

Rocco Fortuna · Answer 2 · 2020-09-17T14:08:58.377

2

I think you're missing a self. All (EDIT: non static, nor abstract) class methods should have a parameter which is typically named self, like so:

class Logger():
    @staticmethod
    def get_timestamp():
        ...

    def print_log(self, color, write_level, msg):
        ...

    def log_level_print(self, log_level, write_level, msg):
        ...


demo = Logger()
print(demo.log_level_print('ERROR','ssdsd','sdsdsd'))

edited Sep 17 '20 at 14:08

answered Sep 17 '20 at 11:50

Rocco Fortuna

300
1
11

@Tomerikoo, I've edited it a couple of minutes ago (indents). – maciejwww Sep 17 '20 at 12:01
I updated the answer to conform with your feedback, let me know if there's still something wrong. – Rocco Fortuna Sep 17 '20 at 14:10
@Tomerikoo, because no one had approved my edit by the time. – maciejwww Sep 17 '20 at 19:34
@maciejwww oh I didn't notice you were not the OP... ^_^ – Tomerikoo Sep 18 '20 at 08:25

score 1 · Answer 3 · edited Sep 17 '20 at 12:08

As mentioned you need to call self and scondly it will still throw error if bcolors is not specified. You need to call bcolors. I am assuming that it is some another dependency which you have not specified.

Here is a sample.

class Logger:
    @staticmethod
    def get_timestamp(self):
        import datetime
        return datetime.datetime.utcnow()

    def print_log(self, color, write_level, msg):
        return color

    def log_level_print(self, log_level, write_level, msg):

        bcolors = []  # temporary empty list

        if log_level == 'ERROR':
            return self.print_log(bcolors.FAIL, write_level, msg)
        if log_level == 'WARN':
            return self.print_log(bcolors.WARNING, write_level, msg)
        if log_level == 'INFO':
            return self.print_log(bcolors.OKGREEN, write_level, msg)
        if log_level == 'DEBUG':
            return self.print_log(bcolors.OKBLUE, write_level, msg)
        else:
            print(f"{Logger.get_timestamp()} {bcolors.FAIL}: Invalid LOG type{bcolors.ENDC}")
            return

demo = Logger()
print(demo.log_level_print('ERROR','ssdsd','sdsdsd'))

static methods does not need self as a parameter. I am still getting print_log is not defined error!, I added self to other function — Jithin Zacharia, Sep 17 '20 at 12:05
Did you really add `self.` before `print_log`? This code works for me like in my answer. — maciejwww, Sep 17 '20 at 12:07
Yes I have added self to the print_log but not to static function.But I am still getting the same error — Jithin Zacharia, Sep 17 '20 at 12:09

Function name is not defined in a Python class

3 Answers3