I have defined a class and want to add an instance to a list. How do I do that? I have tried...
class MyClass:
var1=''
var2=''
thelist = []
instance = MyClass()
instance.var1 = "hello"
instance.var2 = "world"
thelist.extend(instance)
and I am getting a
TypeError: iteration over non-sequence
You want list.append(), not list.extend():
thelist.append(instance)
list.extend() expects a sequence of elements to add, adding them all to the list. You have just one element, in which case you need to use list.append().
From More on Lists in the Python tutorial:
list.append(x)
Add an item to the end of the list; equivalent toa[len(a):] = [x].
list.extend(L)
Extend the list by appending all the items in the given list; equivalent toa[len(a):] = L.
Emphasis mine.
Demo:
>>> class MyClass:
... var1=''
... var2=''
...
>>> thelist = []
>>> instance = MyClass()
>>> instance.var1 = "hello"
>>> instance.var2 = "world"
>>> thelist.append(instance)
>>> thelist
[<__main__.MyClass instance at 0x106d19d40>]
>>> thelist[0].var1
'hello'
