9.1. Comprehensions Nesting¶
9.1.1. Nested Comprehensions¶
DATA = [{'lastname': 'Jiménez'},
{'firstname': 'Mark', 'lastname': 'Watney'},
{'firstname': 'Иван'},
{'firstname': 'Jan', 'lastname': 'Twardowski', 'born': 1961},
{'firstname': 'Melissa', 'lastname': 'Lewis'}]
fieldnames = set(key
for row in DATA
for key in row.keys()
)
print(fieldnames)
# {'born', 'lastname', 'firstname'}
DATA = [{'lastname': 'Jiménez'},
{'firstname': 'Mark', 'lastname': 'Watney'},
{'firstname': 'Иван'},
{'firstname': 'Jan', 'lastname': 'Twardowski', 'born': 1961},
{'firstname': 'Melissa', 'lastname': 'Lewis'}]
fieldnames = set()
fieldnames.update(key
for row in DATA
for key in row.keys()
)
print(fieldnames)
# {'born', 'lastname', 'firstname'}
DATA = [{'lastname': 'Jiménez'},
{'firstname': 'Mark', 'lastname': 'Watney'},
{'firstname': 'Иван'},
{'firstname': 'Jan', 'lastname': 'Twardowski', 'born': 1961},
{'firstname': 'Melissa', 'lastname': 'Lewis'}]
fieldnames = set()
fieldnames.update(key for row in DATA for key in row.keys())
print(fieldnames)
# {'born', 'lastname', 'firstname'}
9.1.2. Generator comprehensions¶
DATA = [{'lastname': 'Jiménez'},
{'firstname': 'Mark', 'lastname': 'Watney'},
{'firstname': 'Иван'},
{'firstname': 'Jan', 'lastname': 'Twardowski', 'born': 1961},
{'firstname': 'Melissa', 'lastname': 'Lewis'}]
fieldnames = set()
fieldnames.add(key
for row in DATA
for key in row.keys()
)
print(fieldnames)
# {<generator object <genexpr> at 0x1179a0a50>}
9.1.3. Assignments¶
Todo
Create assignments