python container summary
- 2020-05-27 06:23:40
- OfStack
python container summary
list
An array variable
tuple
Immutable array
dict
Dictionary of key-value pairs (key-value) (dictionary)
Initialization:
a={ ' lyt':90}
Add:
a[ ' zxw']=91
Access:
1.a[key]
Nothing can go wrong
2.a.get(key)
There is no return None
3.a.get(key,val1)
Does not exist to return the specified val1
# # # # :
>>>key in a
True/False
Delete:
a.pop(key)
The corresponding val is returned and no error is reported
Note that key must be immutable variables such as strings, integers, and tuples. Not an array.
>>> a
[1, 2, 3]
>>> b
(1, 2)
>>> d
{'lyt': 90}
>>> d[a]=99
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: unhashable type: 'list'
>>> d[b]=99
>>> d
{(1, 2): 99, 'lyt': 90}
set
Does not contain a collection of duplicate key
create
One list needs to be provided
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