michael at MacBook-Pro in ~/Dropbox/Projects/cs88/cs88/src/assets/slides/sp24 on main
👉 python3 -i 09-Mutable_Data.py
+=, Before: [1, 2, 3]
+=, After: [1, 2, 3, 4]
=, Before: [10, 9, 8]
=, After: [10, 9, 8, 7]
=, Before: [10, 9, 8]
=, After: [10, 9, 8, 7]
Traceback (most recent call last):
  File "/Users/michael/Dropbox/Projects/cs88/cs88/src/assets/slides/sp24/09-Mutable_Data.py", line 128, in <module>
    counter_fun()
  File "/Users/michael/Dropbox/Projects/cs88/cs88/src/assets/slides/sp24/09-Mutable_Data.py", line 125, in counter_fun
    counter += 1
    ^^^^^^^
UnboundLocalError: cannot access local variable 'counter' where it is not associated with a value
>>>
>>>
>>>
>>> course
{'name': 'Comp Structures in Data Science', 'number': 'C88C', 'room': '155 Dwinelle Hall'}
>>> course['name']
'Comp Structures in Data Science'
>>> course.get('name')
'Comp Structures in Data Science'
>>> course['time']
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
KeyError: 'time'
>>> course['time'] = '2:00 pm'
>>> course
{'name': 'Comp Structures in Data Science', 'number': 'C88C', 'room': '155 Dwinelle Hall', 'time': '2:00 pm'}
>>> course['students'] = []
>>> course['students']
[]
>>> course['students'] += [ 'Michael']
>>> course['students']
['Michael']
>>> 'instructor' in course
False
>>> 'number' in course
True
>>> course
{'name': 'Comp Structures in Data Science', 'number': 'C88C', 'room': '155 Dwinelle Hall', 'time': '2:00 pm', 'students': ['Michael']}
>>> 'C88C' in course
False
>>> course['students'] += [ 'Viper']
>>> course
{'name': 'Comp Structures in Data Science', 'number': 'C88C', 'room': '155 Dwinelle Hall', 'time': '2:00 pm', 'students': ['Michael', 'Viper']}
>>>
>>>
>>> text = 'One upon a time'
>>> { word : len(word) for word in text.split() }
{'One': 3, 'upon': 4, 'a': 1, 'time': 4}
>>> { num : num * num for num in range(10) }
{0: 0, 1: 1, 2: 4, 3: 9, 4: 16, 5: 25, 6: 36, 7: 49, 8: 64, 9: 81}
>>> [ x * x for x in range(10) ]
[0, 1, 4, 9, 16, 25, 36, 49, 64, 81]
>>> course
{'name': 'Comp Structures in Data Science', 'number': 'C88C', 'room': '155 Dwinelle Hall', 'time': '2:00 pm', 'students': ['Michael', 'Viper']}
>>> course.keys()
dict_keys(['name', 'number', 'room', 'time', 'students'])
>>> course.values()
dict_values(['Comp Structures in Data Science', 'C88C', '155 Dwinelle Hall', '2:00 pm', ['Michael', 'Viper']])
>>> course.values()
dict_values(['Comp Structures in Data Science', 'C88C', '155 Dwinelle Hall', '2:00 pm', ['Michael', 'Viper']])
>>>
>>>
>>> course.item()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'dict' object has no attribute 'item'. Did you mean: 'items'?
>>> course.items()
dict_items([('name', 'Comp Structures in Data Science'), ('number', 'C88C'), ('room', '155 Dwinelle Hall'), ('time', '2:00 pm'), ('students', ['Michael', 'Viper'])])
>>> for key, value in course.items():
...     print(f"key: {key}, value: {value}")
...
key: name, value: Comp Structures in Data Science
key: number, value: C88C
key: room, value: 155 Dwinelle Hall
key: time, value: 2:00 pm
key: students, value: ['Michael', 'Viper']
>>> OrderedDict
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'OrderedDict' is not defined
>>> num = 88
>>> num
88
>>> type(num)
<class 'int'>
>>>
>>>
>>> id(num)
4318572056
>>> id(course)
4306129216
>>> alist = [1, 2, 3, 4]
>>> alist == [1, 2, 3, 4]
True
>>> alist is [1, 2, 3, 4]
False
>>> blist = [1, 2, 3, 4]
>>> alist
[1, 2, 3, 4]
>>> blist
[1, 2, 3, 4]
>>> alist == blist
True
>>> alist.append(5)
>>> alist
[1, 2, 3, 4, 5]
>>> alist == blist
False
>>> blist
[1, 2, 3, 4]
>>>
>>>
>>>
>>> clist = alist
>>> clist
[1, 2, 3, 4, 5]
>>> alist == clist
True
>>> alist.append(6)
>>> alist == clist
True
>>> alist
[1, 2, 3, 4, 5, 6]
>>> clist
[1, 2, 3, 4, 5, 6]
>>> alist is clist
True
>>> clist is alist
True
>>>

>>>
>>> c2 = course
>>> c2
{'name': 'Comp Structures in Data Science', 'number': 'C88C', 'room': '155 Dwinelle Hall', 'time': '2:00 pm', 'students': ['Michael', 'Viper']}
>>> c2['time'] = '3:00 pm'
>>> course
{'name': 'Comp Structures in Data Science', 'number': 'C88C', 'room': '155 Dwinelle Hall', 'time': '3:00 pm', 'students': ['Michael', 'Viper']}
>>> c2 is course
True
>>>