How to check if variable is a specific class in python?

Question

I have a variable "myvar" that when I print out its type(myvar)

the output is:

<class 'my.object.kind'>

If I have a list of 10 variables including strings and variables of that kind.. how can I construct an if statement to check whether an object in the list "mylist" is of <type 'my.object.kind'>?

It's not clear what you're trying to do. Are you trying to see if the list contains an element of type my.object.kind? Are you trying to get the types of all the elements of the list? — user2357112
– user2357112, Commented Aug 8, 2013 at 4:09
isinstance() is the python built-in-function that you're looking for. docs.python.org/2/library/functions.html#isinstance — Jonathan Vanasco
– Jonathan Vanasco, Commented Aug 8, 2013 at 4:14

glglgl · Accepted Answer · 2013-08-08 04:50:52Z

58

Use isinstance, this will return true even if it is an instance of the subclass:

if isinstance(x, my.object.kind)

Or:

type(x) == my.object.kind #3.x

If you want to test all in the list:

if any(isinstance(x, my.object.kind) for x in alist)

edited Aug 8, 2013 at 4:50

glglgl

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answered Aug 8, 2013 at 4:08

zhangyangyu

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3 Comments

Owen Over a year ago

The post asks for a way to apply this to a list

SebMa Over a year ago

@zhangyangyu I have type( x ) that shows <class 'argparse.Namespace'> but then type( x ) == argparse.Namespace.kindsays *** AttributeError: type object 'Namespace' has no attribute 'kind'

zhangyangyu Over a year ago

@SebMa my.object.kind is the class the OP has, not an attribute indicating the type. You should use type(x) == argparse.Namespace.

Owen · Accepted Answer · 2013-08-08 04:10:09Z

0

if any(map(lambda x: isinstance(x, my.object.kind), my_list_of_objects)):
    print "Found one!"

answered Aug 8, 2013 at 4:10

Owen

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1 Comment

tobyodavies Over a year ago

map and lambda are not necessary here, use a generator comprehension.

lazy functor · Accepted Answer · 2013-08-08 04:11:11Z

0

Try

if any([isinstance(x, my.object.kind) for x in mylist]):
    print "found"

answered Aug 8, 2013 at 4:11

lazy functor

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