Getting the class name of an instance

Question

How do I find out a name of class that created an instance of an object in Python if the function I am doing this from is the base class of which the class of the instance has been derived   Was thinking maybe the inspect module might have helped me out here  but it doesn t seem to give me what I want  And short of parsing the   class   member  I m not sure how to get at this information

User · Answer

type      gt  gt  gt  class A          def whoami self               print type self    name         gt  gt  gt   gt  gt  gt  class B A           pass      gt  gt  gt   gt  gt  gt   gt  gt  gt  o   B    gt  gt  gt  o whoami    B   gt  gt  gt

User · Answer

class A    pass  a   A   str a   class      The sample code above  when input in the interactive interpreter  will produce    main   A  as opposed to  A  which is produced if the   name   attribute is invoked  By simply passing the result of A   class   to the str constructor the parsing is handled for you  However  you could also use the following code if you want something more explicit     0   1   format a   class     module   a   class     name      This behavior can be preferable if you have classes with the same name defined in separate modules   The sample code provided above was tested in Python 2 7 5

User · Answer

To get instance classname   type instance    name     or  instance   class     name     both are the same

User · Answer

In Python 2  type instance    name      instance   class     name     if class A is defined like class A            type instance     instance   class     if class A is defined like class A object          Example   gt  gt  gt  class aclass object         pass      gt  gt  gt  a   aclass    gt  gt  gt  type a   lt class    main   aclass  gt   gt  gt  gt  a   class    lt class    main   aclass  gt   gt  gt  gt   gt  gt  gt  type a    name    aclass   gt  gt  gt   gt  gt  gt  a   class     name    aclass   gt  gt  gt     gt  gt  gt  class bclass          pass      gt  gt  gt  b   bclass    gt  gt  gt   gt  gt  gt  type b   lt type  instance  gt   gt  gt  gt  b   class    lt class   main   bclass at 0xb765047c gt   gt  gt  gt  type b    name    instance   gt  gt  gt   gt  gt  gt  b   class     name    bclass   gt  gt  gt

User · Answer

type      gt  gt  gt  class A          def whoami self               print type self    name         gt  gt  gt   gt  gt  gt  class B A           pass      gt  gt  gt   gt  gt  gt   gt  gt  gt  o   B    gt  gt  gt  o whoami    B   gt  gt  gt

User · Answer

type      gt  gt  gt  class A          def whoami self               print type self    name         gt  gt  gt   gt  gt  gt  class B A           pass      gt  gt  gt   gt  gt  gt   gt  gt  gt  o   B    gt  gt  gt  o whoami    B   gt  gt  gt

User · Answer

You can simply use   qualname   which stands for qualified name of a function or class Example   gt  gt  gt  class C          class D              def meth self                   pass      gt  gt  gt  C   qualname    C   gt  gt  gt  C D   qualname    C D   gt  gt  gt  C D meth   qualname    C D meth   documentation link qualname

User · Answer

Apart from grabbing the special   name   attribute  you might find yourself in need of the qualified name for a given class function  This is done by grabbing the types   qualname     In most cases  these will be exactly the same  but  when dealing with nested classes methods these differ in the output you get  For example   class Spam      def meth self           pass     class Bar          pass   gt  gt  gt  s   Spam    gt  gt  gt  type s    name     Spam   gt  gt  gt  type s    qualname    Spam   gt  gt  gt  type s  Bar   name           type not needed here  Bar   gt  gt  gt  type s  Bar   qualname       type not needed here   Spam Bar   gt  gt  gt  type s  meth   name    meth   gt  gt  gt  type s  meth   qualname    Spam meth    Since introspection is what you re after  this is always you might want to consider

User · Answer

Good question   Here s a simple example based on GHZ s which might help someone    gt  gt  gt  class person object           def init self name               self name name         def info self              print  My name is  0   I am a  1   format self name self   class     name     gt  gt  gt  bob   person name  Robert    gt  gt  gt  bob info   My name is Robert  I am a person

User · Answer

Have you tried the   name   attribute of the class  ie type x    name   will give you the name of the class  which I think is what you want    gt  gt  gt  import itertools  gt  gt  gt  x   itertools count 0   gt  gt  gt  type x    name    count    If you re still using Python 2  note that the above method works with new-style classes only  in Python 3  all classes are  new-style  classes   Your code might use some old-style classes  The following works for both   x   class     name

User · Answer

Apart from grabbing the special   name   attribute  you might find yourself in need of the qualified name for a given class function  This is done by grabbing the types   qualname     In most cases  these will be exactly the same  but  when dealing with nested classes methods these differ in the output you get  For example   class Spam      def meth self           pass     class Bar          pass   gt  gt  gt  s   Spam    gt  gt  gt  type s    name     Spam   gt  gt  gt  type s    qualname    Spam   gt  gt  gt  type s  Bar   name           type not needed here  Bar   gt  gt  gt  type s  Bar   qualname       type not needed here   Spam Bar   gt  gt  gt  type s  meth   name    meth   gt  gt  gt  type s  meth   qualname    Spam meth    Since introspection is what you re after  this is always you might want to consider

User · Answer

Do you want the name of the class as a string   instance   class     name

User · Answer

type      gt  gt  gt  class A          def whoami self               print type self    name         gt  gt  gt   gt  gt  gt  class B A           pass      gt  gt  gt   gt  gt  gt   gt  gt  gt  o   B    gt  gt  gt  o whoami    B   gt  gt  gt

User · Answer

To get instance classname   type instance    name     or  instance   class     name     both are the same

User · Answer

Do you want the name of the class as a string   instance   class     name

User · Answer

Alternatively you can use the classmethod decorator   class A       classmethod     def get classname cls           return cls   name        def use classname self           return self get classname     Usage    gt  gt  gt  A get classname    A   gt  gt  gt  a   A    gt  gt  gt  a get classname    A   gt  gt  gt  a use classname    A

User · Answer

Have you tried the   name   attribute of the class  ie type x    name   will give you the name of the class  which I think is what you want    gt  gt  gt  import itertools  gt  gt  gt  x   itertools count 0   gt  gt  gt  type x    name    count    If you re still using Python 2  note that the above method works with new-style classes only  in Python 3  all classes are  new-style  classes   Your code might use some old-style classes  The following works for both   x   class     name

User · Answer

Alternatively you can use the classmethod decorator   class A       classmethod     def get classname cls           return cls   name        def use classname self           return self get classname     Usage    gt  gt  gt  A get classname    A   gt  gt  gt  a   A    gt  gt  gt  a get classname    A   gt  gt  gt  a use classname    A

User · Answer

Do you want the name of the class as a string   instance   class     name

User · Answer

Good question   Here s a simple example based on GHZ s which might help someone    gt  gt  gt  class person object           def init self name               self name name         def info self              print  My name is  0   I am a  1   format self name self   class     name     gt  gt  gt  bob   person name  Robert    gt  gt  gt  bob info   My name is Robert  I am a person

User · Answer

Have you tried the   name   attribute of the class  ie type x    name   will give you the name of the class  which I think is what you want    gt  gt  gt  import itertools  gt  gt  gt  x   itertools count 0   gt  gt  gt  type x    name    count    If you re still using Python 2  note that the above method works with new-style classes only  in Python 3  all classes are  new-style  classes   Your code might use some old-style classes  The following works for both   x   class     name

User · Answer

Have you tried the   name   attribute of the class  ie type x    name   will give you the name of the class  which I think is what you want    gt  gt  gt  import itertools  gt  gt  gt  x   itertools count 0   gt  gt  gt  type x    name    count    If you re still using Python 2  note that the above method works with new-style classes only  in Python 3  all classes are  new-style  classes   Your code might use some old-style classes  The following works for both   x   class     name

User · Answer

In Python 2  type instance    name      instance   class     name     if class A is defined like class A            type instance     instance   class     if class A is defined like class A object          Example   gt  gt  gt  class aclass object         pass      gt  gt  gt  a   aclass    gt  gt  gt  type a   lt class    main   aclass  gt   gt  gt  gt  a   class    lt class    main   aclass  gt   gt  gt  gt   gt  gt  gt  type a    name    aclass   gt  gt  gt   gt  gt  gt  a   class     name    aclass   gt  gt  gt     gt  gt  gt  class bclass          pass      gt  gt  gt  b   bclass    gt  gt  gt   gt  gt  gt  type b   lt type  instance  gt   gt  gt  gt  b   class    lt class   main   bclass at 0xb765047c gt   gt  gt  gt  type b    name    instance   gt  gt  gt   gt  gt  gt  b   class     name    bclass   gt  gt  gt

User · Answer

You can simply use   qualname   which stands for qualified name of a function or class Example   gt  gt  gt  class C          class D              def meth self                   pass      gt  gt  gt  C   qualname    C   gt  gt  gt  C D   qualname    C D   gt  gt  gt  C D meth   qualname    C D meth   documentation link qualname

User · Answer

Do you want the name of the class as a string   instance   class     name

User · Answer

class A    pass  a   A   str a   class      The sample code above  when input in the interactive interpreter  will produce    main   A  as opposed to  A  which is produced if the   name   attribute is invoked  By simply passing the result of A   class   to the str constructor the parsing is handled for you  However  you could also use the following code if you want something more explicit     0   1   format a   class     module   a   class     name      This behavior can be preferable if you have classes with the same name defined in separate modules   The sample code provided above was tested in Python 2 7 5

[python] Getting the class name of an instance?

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