+- Python Forum (https://python-forum.io)
+-- Forum: Python Coding (https://python-forum.io/forum-7.html)
+--- Forum: General Coding Help (https://python-forum.io/forum-8.html)
+--- Thread: what is the doc parameter of property? (/thread-17400.html)
what is the doc parameter of property? - microphone_head - Apr-09-2019
Hi all.
I was doing some light reading and noticed a line in sprite.py file that I didn't totally understand. The lines of code were found in the DirtySprite class. I guess its declaring a property in the sprite module for the class DirtySprite, but I thought all declarators like that had to be declared like:
@propertyThe lines i'm interested in are:
visible = property(lambda self: self._get_visible(),
lambda self, value: self._set_visible(value),
doc="you can make this sprite disappear without "
"removing it from the group,\n"
"assign 0 for invisible and 1 for visible")Can anyone tell me anything about the doc parameter? 
FYI: I'm running a RaspberryPi2B+
RE: visible = property - Yoriz - Apr-09-2019
See python docs https://docs.python.org/3/library/functions.html?highlight=property#property
doc creates a docstring for the attribute.
visible = property(lambda self: self._get_visible(),
lambda self, value: self._set_visible(value),
doc="you can make this sprite disappear without "
"removing it from the group,\n"
"assign 0 for invisible and 1 for visible")
help(visible)Output:Help on property:
you can make this sprite disappear without removing it from the group,
assign 0 for invisible and 1 for visiblehelp(property)
Output:class property(object)
| property(fget=None, fset=None, fdel=None, doc=None)
|
| Property attribute.
|
| fget
| function to be used for getting an attribute value
| fset
| function to be used for setting an attribute value
| fdel
| function to be used for del'ing an attribute
| doc
| docstring
|
| Typical use is to define a managed attribute x:
|
| class C(object):
| def getx(self): return self._x
| def setx(self, value): self._x = value
| def delx(self): del self._x
| x = property(getx, setx, delx, "I'm the 'x' property.")
|
| Decorators make defining new properties or modifying existing ones easy:
|
| class C(object):
| @property
| def x(self):
| "I am the 'x' property."
| return self._x
| @x.setter
| def x(self, value):
| self._x = value
| @x.deleter
| def x(self):
| del self._x
|
| Methods defined here:
|
| __delete__(self, instance, /)
| Delete an attribute of instance.
|
| __get__(self, instance, owner, /)
| Return an attribute of instance, which is of type owner.
|
| __getattribute__(self, name, /)
| Return getattr(self, name).
|
| __init__(self, /, *args, **kwargs)
| Initialize self. See help(type(self)) for accurate signature.
|
| __set__(self, instance, value, /)
| Set an attribute of instance to value.
|
| deleter(...)
| Descriptor to change the deleter on a property.
|
| getter(...)
| Descriptor to change the getter on a property.
|
| setter(...)
| Descriptor to change the setter on a property.
|
| ----------------------------------------------------------------------
| Static methods defined here:
|
| __new__(*args, **kwargs) from builtins.type
| Create and return a new object. See help(type) for accurate signature.
|
| ----------------------------------------------------------------------
| Data descriptors defined here:
|
| __isabstractmethod__
|
| fdel
|
| fget
|
| fsetRE: what is the doc parameter of property? - microphone_head - Apr-11-2019
I've been following up the help you've given so far, and found a style of doc string that I would like to apply to my code, Numpy.
Thanks for the help. I never thought of using the "help" function on my own code before , a nice eye opener.
This looks really useful.