Python: Reassign value to variable (using a function)
Possible Duplicate:
Python: How do I pass a variable by reference?
How can I reassign a value to a variable that is passed as a function argument?
For instance, what I am looking to do is:
foo = True
def convert(foo):
if foo == True:
foo = 'on'
elif foo == False:
foo = 'off'
return foo
where foo
is now a string. The problem with the method above is that in order to change foo
from a boolean type to a string type the following must be passed:
foo = convert(foo)
whereas I am looking to do something like:
convert(foo)
or,
foo.convert()
Any ideas?
foo = convert(foo)
is the cleanest and most explicit way to achive this. This is the way most people would recommend, if you are sure you even need to reassign a string to a bool
variable.
foo.convert()
is something you can do on an instance of a class that you need to define. You can do it, but it's not worth the hassle. Just reassign the variable, that's it.
convert(foo) # actually, just convert()
can also work, but you'd have to use the global
keyword in the convert
function. This is not recommended, especially when it's so easy to avoid.
In [1]: foo = True
In [2]: def convert():
...: global foo
...: foo = 'on' if foo else 'off'
...:
In [3]: convert()
In [4]: foo
Out[4]: 'on'
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