Formatting of if condition can be improved.

[sainadh-d]

Operating system: Mac OS X Mojave
Python version: Python 3.6.7
Black version: 18.9b0
Does also happen on master: Yes

I have a piece of code which looks like

class MyClass:
    def my_func(self, check=False):
        flag = False
        try:
            configuration = self.get_config_from_db()
            if check:
                if 'expected_flavour' in configuration.get('flavours', []) and app_settings[0].upper() in configuration.get('settings', []):
                    flag = True
        except:
            pass
        return flag

Upon running black on this

black -S -l 120 temp.py

I get

class MyClass:
    def my_func(self, check=False):
        flag = False
        try:
            configuration = self.get_config_from_db()
            if check:
                if 'expected_flavour' in configuration.get('flavours', []) and app_settings[
                    0
                ].upper() in configuration.get('settings', []):
                    flag = True
        except:
            pass
        return flag

Formatting of the if condition above is not readable.

if 'expected_flavour' in configuration.get('flavours', []) and app_settings[
      0
].upper() in configuration.get('settings', []):

IMO the following would be more readable, which is done when there are 3 or more checks in if

class MyClass:
    def my_func(self, check=False):
        flag = False
        try:
            configuration = self.get_config_from_db()
            if check:
                if (
                    'expected_flavour' in configuration.get('flavours', [])
                    and app_settings[0].upper() in configuration.get('settings', [])
                ):
                    flag = True
        except:
            pass
        return flag

[sainadh-goibibo]

@JelleZijlstra @ambv Pls check

[JelleZijlstra]

I agree that the formatting with index expressions on their own line isn't great and that your proposed formatting looks nicer in this case. I haven't looked at how realistic it is to implement in general though, and maybe this change would lead to worse formatting in some other case.

[ambv]

We should at least try to make Black not choose to split on indexes if optional parentheses can yield nicer formattings.

[MikeFalowski]

Still happen in version 19. It would be really nice improvement.

[miriaford]

Could any contributor please point us to how we can modify this behavior ourselves? I'm willing to fork Black and hack the source code.

[felix-hilden]

I believe this is essentially the same request as the newer #2156, which has some more discussion (though it was initially rejected) and associated PRs. I'll close this issue in favor of it!