What is the cleanest way to commit data stored in instances of a dataclass contained in a list to SQLite with sqlite3's executemany?
For example:
@dataclass
class Person:
name: str
age: int
a = Person("Alice", 21)
b = Person("Bob", 22)
c = Person("Charlie", 23)
people = [a, b, c]
# ...
cursor.executemany(f"INSERT INTO {table} ({headers}) ({placeholders})", people) # <-- fails, obviously
Is there a built-in mechanism that does the work for me (goes over each attribute of the dataclass), or an idiomatic way, or, if not, how do I implement an adapter for this without explicitly listing the attributes one by one?
I could convert it to a list of tuples, that works out of the box, yet feels redundant.
Use the astuple() function to convert the dataclass instances to tuples.
from dataclasses import dataclass, fields, astuple
headers = ','.join(f.name for f in fields(Person))
people = map(astuple, [a, b, c])
placeholders = ','.join(['?'] * len(headers))
table = 'persons'
cursor.executemany(f"INSERT INTO {table} ({headers}) ({placeholders})", people)