8.2. JSON String¶
8.2.1. SetUp¶
>>> import json
8.2.2. Mapping¶
json.dumps(DATA: dict) -> str- dict to JSONjson.loads(DATA: str) -> dict- JSON to dict
Serialize mapping to JSON:
>>> DATA = {
... 'firstname': 'Mark',
... 'lastname': 'Watney',
... }
>>>
>>> result = json.dumps(DATA)
>>> print(result)
{"firstname": "Mark", "lastname": "Watney"}
Deserialize JSON to mapping:
>>> DATA = """{
... "firstname": "Mark",
... "lastname": "Watney"
... }"""
>>>
>>> result = json.loads(DATA)
>>> print(result)
{'firstname': 'Mark', 'lastname': 'Watney'}
8.2.3. List of Mappings to JSON¶
json.dumps(data: Iterable[dict]) -> str- list[dict] to JSONjson.loads(data: str) -> list[dict]- JSON to list[dict]
Serialize list of mappings to JSON:
>>> DATA = [
... {'firstname': 'Melissa', 'lastname': 'Lewis'},
... {'firstname': 'Rick', 'lastname': 'Martinez'},
... {'firstname': 'Mark', 'lastname': 'Watney'},
... ]
>>>
>>> result = json.dumps(DATA)
>>> print(result)
[{"firstname": "Melissa", "lastname": "Lewis"},
{"firstname": "Rick", "lastname": "Martinez"},
{"firstname": "Mark", "lastname": "Watney"}]
Deserialize JSON to list of mappings:
>>> DATA = """[
... {"firstname": "Melissa", "lastname": "Lewis"},
... {"firstname": "Rick", "lastname": "Martinez"},
... {"firstname": "Mark", "lastname": "Watney"}
... ]"""
>>>
>>> result = json.loads(DATA)
>>> print(result)
[{'firstname': 'Melissa', 'lastname': 'Lewis'},
{'firstname': 'Rick', 'lastname': 'Martinez'},
{'firstname': 'Mark', 'lastname': 'Watney'}]
8.2.4. List of Iterable¶
json.dumps(data: list[Iterable]) -> str- list[Iterable] to JSONjson.loads(data: str) -> list[list]- JSON to list[Iterable]
Serialize list of iterables to JSON:
>>> DATA = [
... ('Sepal length', 'Sepal width', 'Petal length', 'Petal width', 'Species'),
... (5.8, 2.7, 5.1, 1.9, 'virginica'),
... (5.1, 3.5, 1.4, 0.2, 'setosa'),
... (5.7, 2.8, 4.1, 1.3, 'versicolor')
... ]
>>>
>>> result = json.dumps(DATA)
>>> print(result)
[["Sepal length", "Sepal width", "Petal length", "Petal width", "Species"],
[5.8, 2.7, 5.1, 1.9, "virginica"],
[5.1, 3.5, 1.4, 0.2, "setosa"],
[5.7, 2.8, 4.1, 1.3, "versicolor"]]
Deserialize JSON to list of iterables:
>>> DATA = """[
... ["Sepal length", "Sepal width", "Petal length", "Petal width", "Species"],
... [5.8, 2.7, 5.1, 1.9, "virginica"],
... [5.1, 3.5, 1.4, 0.2, "setosa"],
... [5.7, 2.8, 4.1, 1.3, "versicolor"]
... ]"""
>>>
>>> result = json.loads(DATA)
>>> print(result)
[['Sepal length', 'Sepal width', 'Petal length', 'Petal width', 'Species'],
[5.8, 2.7, 5.1, 1.9, 'virginica'],
[5.1, 3.5, 1.4, 0.2, 'setosa'],
[5.7, 2.8, 4.1, 1.3, 'versicolor']]
8.2.5. Assignments¶
"""
* Assignment: JSON String DumpFlat
* Complexity: easy
* Lines of code: 1 lines
* Time: 2 min
English:
1. Dump `DATA` to JSON format
2. Run doctests - all must succeed
Polish:
1. Zrzuć `DATA` do formatu JSON
2. Uruchom doctesty - wszystkie muszą się powieść
Tests:
>>> import sys; sys.tracebacklimit = 0
>>> assert result is not Ellipsis, \
'Assign result to variable: `result`'
>>> assert type(result) is str, \
'Variable `result` has invalid type, should be str'
>>> assert len(result) > 0, \
'Variable `result` should not be empty'
>>> print(result)
[5.1, 3.5, 1.4, 0.2, "setosa"]
"""
import json
DATA = (5.1, 3.5, 1.4, 0.2, 'setosa')
# dump DATA to JSON format
# type: str
result = ...
"""
* Assignment: JSON String DumpNested
* Complexity: easy
* Lines of code: 1 lines
* Time: 2 min
English:
1. Dump `DATA` to JSON format
2. Run doctests - all must succeed
Polish:
1. Zrzuć `DATA` do formatu JSON
2. Uruchom doctesty - wszystkie muszą się powieść
Tests:
>>> import sys; sys.tracebacklimit = 0
>>> assert result is not Ellipsis, \
'Assign result to variable: `result`'
>>> assert type(result) is str, \
'Variable `result` has invalid type, should be str'
>>> assert len(result) > 0, \
'Variable `result` should not be empty'
>>> print(result) # doctest: +NORMALIZE_WHITESPACE
[["Sepal length", "Sepal width", "Petal length", "Petal width", "Species"],
[5.8, 2.7, 5.1, 1.9, "virginica"],
[5.1, 3.5, 1.4, 0.2, "setosa"],
[5.7, 2.8, 4.1, 1.3, "versicolor"],
[6.3, 2.9, 5.6, 1.8, "virginica"],
[6.4, 3.2, 4.5, 1.5, "versicolor"],
[4.7, 3.2, 1.3, 0.2, "setosa"]]
"""
import json
DATA = [
('Sepal length', 'Sepal width', 'Petal length', 'Petal width', 'Species'),
(5.8, 2.7, 5.1, 1.9, 'virginica'),
(5.1, 3.5, 1.4, 0.2, 'setosa'),
(5.7, 2.8, 4.1, 1.3, 'versicolor'),
(6.3, 2.9, 5.6, 1.8, 'virginica'),
(6.4, 3.2, 4.5, 1.5, 'versicolor'),
(4.7, 3.2, 1.3, 0.2, 'setosa')]
# dump DATA to JSON format
# type: str
result = ...
"""
* Assignment: JSON String LoadObject
* Complexity: easy
* Lines of code: 1 lines
* Time: 2 min
English:
1. Load `DATA` from JSON format
2. Convert data to `result: dict`
3. Do not add header as a first line
4. Run doctests - all must succeed
Polish:
1. Wczytaj `DATA` z formatu JSON
2. Przekonwertuj dane do `result: dict`
3. Nie dodawaj nagłówka jako pierwsza linia
4. Uruchom doctesty - wszystkie muszą się powieść
Tests:
>>> import sys; sys.tracebacklimit = 0
>>> assert result is not Ellipsis, \
'Assign result to variable: `result`'
>>> assert type(result) is dict, \
'Variable `result` has invalid type, should be dict'
>>> assert len(result) > 0, \
'Variable `result` should not be empty'
>>> result # doctest: +NORMALIZE_WHITESPACE
{'Sepal length': 5.1,
'Sepal width': 3.5,
'Petal length': 1.4,
'Petal width': 0.2,
'Species': 'setosa'}
"""
import json
DATA = """
{
"Sepal length": 5.1,
"Sepal width": 3.5,
"Petal length": 1.4,
"Petal width": 0.2,
"Species": "setosa"
}
"""
# Load `DATA` from JSON format
# type: list[dict]
result = ...
"""
* Assignment: JSON String LoadList
* Complexity: easy
* Lines of code: 1 lines
* Time: 2 min
English:
1. Load `DATA` from JSON format
2. Convert data to `result: list[dict]`
3. Do not add header as a first line
4. Run doctests - all must succeed
Polish:
1. Wczytaj `DATA` z formatu JSON
2. Przekonwertuj dane do `result: list[dict]`
3. Nie dodawaj nagłówka jako pierwsza linia
4. Uruchom doctesty - wszystkie muszą się powieść
Tests:
>>> import sys; sys.tracebacklimit = 0
>>> assert result is not Ellipsis, \
'Assign result to variable: `result`'
>>> assert type(result) is list, \
'Variable `result` has invalid type, should be list'
>>> assert len(result) > 0, \
'Variable `result` should not be empty'
>>> assert all(type(row) is dict for row in result), \
'Variable `result` should be a list[dict]'
>>> result[0] # doctest: +NORMALIZE_WHITESPACE
{'Sepal length': 5.8,
'Sepal width': 2.7,
'Petal length': 5.1,
'Petal width': 1.9,
'Species': 'virginica'}
>>> result # doctest: +NORMALIZE_WHITESPACE
[{'Sepal length': 5.8, 'Sepal width': 2.7, 'Petal length': 5.1,
'Petal width': 1.9, 'Species': 'virginica'},
{'Sepal length': 5.1, 'Sepal width': 3.5, 'Petal length': 1.4,
'Petal width': 0.2, 'Species': 'setosa'},
{'Sepal length': 5.7, 'Sepal width': 2.8, 'Petal length': 4.1,
'Petal width': 1.3, 'Species': 'versicolor'},
{'Sepal length': 6.3, 'Sepal width': 2.9, 'Petal length': 5.6,
'Petal width': 1.8, 'Species': 'virginica'},
{'Sepal length': 6.4, 'Sepal width': 3.2, 'Petal length': 4.5,
'Petal width': 1.5, 'Species': 'versicolor'},
{'Sepal length': 4.7, 'Sepal width': 3.2, 'Petal length': 1.3,
'Petal width': 0.2, 'Species': 'setosa'}]
"""
import json
DATA = (
'[{"Sepal length":5.8,"Sepal width":2.7,"Petal length":5.1,"Petal width":1'
'.9,"Species":"virginica"},{"Sepal length":5.1,"Sepal width":3.5,"Petal le'
'ngth":1.4,"Petal width":0.2,"Species":"setosa"},{"Sepal length":5.7,"Sepa'
'l width":2.8,"Petal length":4.1,"Petal width":1.3,"Species":"versicolor"}'
',{"Sepal length":6.3,"Sepal width":2.9,"Petal length":5.6,"Petal width":1'
'.8,"Species":"virginica"},{"Sepal length":6.4,"Sepal width":3.2,"Petal le'
'ngth":4.5,"Petal width":1.5,"Species":"versicolor"},{"Sepal length":4.7,"'
'Sepal width":3.2,"Petal length":1.3,"Petal width":0.2,"Species":"setosa"}'
']'
)
# Load `DATA` from JSON format
# type: list[dict]
result = ...