Single leading dash in member variable names?

[e.doxtator]

All

Python noob here. Trying to understand a particular syntax:

class stuff:
def __init__(self):
self._bongo = "BongoWorld"

 

[Ian Kelly]

All

Python noob here. Trying to understand a particular syntax:

class stuff:
def __init__(self):
self._bongo = "BongoWorld"

Single leading underscore is a convention indicating that the name
should be considered private and not used externally. It's a softer
version of the double leading underscore that means basically the same
thing but has syntactic significance.

 

[e.doxtator]

Single leading underscore is a convention indicating that the name

should be considered private and not used externally. It's a softer

version of the double leading underscore that means basically the same

thing but has syntactic significance.

Thank you!

PEP 8 says this is bad form. What do you think?

 

[e.doxtator]

Single leading underscore is a convention indicating that the name

should be considered private and not used externally. It's a softer

version of the double leading underscore that means basically the same

thing but has syntactic significance.

Thank you!

PEP 8 says this is bad form. What do you think?

 

[Terry Reedy]

PEP 8 says this is bad form. What do you think?

Please quote the specific statement you want commented. The stdlib
routinely uses _names for internal implementation objects. __ugh is
perhaps never used.

 

[Tim Chase]

Not to jump in with another question(this seems somewhat relevant
to the conversation, maybe not), but is this similar to a
private,public, or protected class similar to the C type langs?

Close, but C-like languages tend to strictly enforce it, while in
Python it's more of a gentleman's agreement. Python doesn't *stop*
you from mucking with them, but you've been advised that, if it
breaks, you get to keep both parts.

-tkc

 

[e.doxtator]

Where does it say that?

Apologies. It's in David Goodger's "Code Like A Pythonista" in the "Naming" section. (http://python.net/~goodger/projects/pycon/2007/idiomatic/handout.html#naming)

 

[Ian Kelly]

Not to jump in with another question(this seems somewhat relevant to the
conversation, maybe not), but is this similar to a private,public, or
protected class similar to the C type langs?

More like "this is an implementation detail and in the future it could
be changed or removed entirely without warning". I consider them
private unless documented otherwise.

 

[Ian Kelly]

Apologies. It's in David Goodger's "Code Like A Pythonista" in the "Naming" section. (http://python.net/~goodger/projects/pycon/2007/idiomatic/handout.html#naming)

That's arguing against double leading underscore, not single leading
underscore. I pretty much agree with it; I rarely use the
name-mangling syntax myself.

 

[mdengler]

[...] David Goodger's "Code Like A Pythonista" in the "Naming" section [says single leading underscore is bad form]. (http://python.net/~goodger/projects/pycon/2007/idiomatic/handout.html#naming)

Looks like it says the opposite:

"[rather than trying to hide attributes with double-leading-underscores, i]t's better to use the single-leading-underscore convention, _internal".

 

[Aahz]

Single leading underscore is a convention indicating that the name
should be considered private and not used externally. It's a softer
version of the double leading underscore that means basically the same
thing but has syntactic significance.

Note that the convention is rooted in an actual semantic meaning for
single underscore:

``from foo import *`` ignores any module global names in foo that start
with a single leading underscore. Obviously, this has little effect for
most Python programs because you DON'T USE ``import *``.