python - Inheritance of built in types. Where did the author obtain the 'self' in the for loop -

class contactlist(list):      def search(self, name):         matching_contacts = []          contact in self:             if name in contact.name:                 matching_contacts.append(contact)             return matching_contacts  class contact:     all_contacts = contactlist()      def __init__(self, name, email):         self.name = name         self.email = email         self.all_contacts.append(self)  print([c.name c in contact.all_contacts.search('john')]) >>>  ['john a'] 

this class author wrote. creates class inherits built in type list. have trouble understanding loop. since author uses loop i.e 'for contact in self' resulting in me thinking self =[] declared somewhere. author not explicitly write leads me assume in parent class there def init method provides self = []. unsure if understanding correct or there else entirely not seeing.

also not understand author obtain contact.name in if statement.

edit

i have added full code. search result produces 'john a' , should include 'john b' have no idea why not working.

self refers actual instance of contactlist. since contactlist subclass of list, list , self can iterated on in loop can list.

you can see list methods using help(list) whilst in interpreter, or reading python documentation or tutorial.

where did contact.name come from? in search() method each element of contactlist (accessed via self) bound in turn contact loop, , element contains attribute named name. example simple class contact:

class contact(object):     def __init__(self, name, phone=none):         self.name = name         self.phone = phone  >>> contacts = contactlist([contact('me','555-1234'), contact('you','555-4321'), contact('someone else')]) >>> contacts.search('you') [<__main__.contact object @ 0x7f258eab0fd0>] >>> contacts.search('nobody') [] >>> contacts.search('e') [<__main__.contact object @ 0x7f258eab0f50>, <__main__.contact object @ 0x7f258eabe050>]    # 'me' , "someone else' 

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note there bug in search() method (or maybe it's error introduced when posting code here?)

return matching_contacts 

is within body of loop , executed on first iteration of loop. means search check first element of contact list. return statement should deindented same level loop this:

class contactlist(list):     def search(self, name):         matching_contacts = []         contact in self:             if name in contact.name:                 matching_contacts.append(contact)         return matching_contacts