python static variable in function
#You can make static variables inside a function in many ways.
#____________________________________________________________#
"""1/You can add attributes to a function, and use it as a
static variable."""
def foo():
foo.counter += 1
print ("Counter is %d" % foo.counter)
foo.counter = 0
#____________________________________________________________#
"""2/If you want the counter initialization code at the top
instead of the bottom, you can create a decorator:"""
def static_vars(**kwargs):
def decorate(func):
for k in kwargs:
setattr(func, k, kwargs[k])
return func
return decorate
#Then use the code like this:
@static_vars(counter=0)
def foo():
foo.counter += 1
print ("Counter is %d" % foo.counter)
#____________________________________________________________#
"""3/Alternatively, if you don't want to setup the variable
outside the function, you can use hasattr() to avoid an
AttributeError exception:"""
def myfunc():
if not hasattr(myfunc, "counter"):
myfunc.counter = 0 # it doesn't exist yet, so initialize it
myfunc.counter += 1
#____________________________________________________________#