import firebird.driver as firebird
import decimal

con = firebird.connect('employee')
cur = con.cursor()
cur.execute("select cast('0.00' as NUMERIC(9,2)) from rdb$database")

val_from_db = cur.fetchone()[0]
val_from_py = decimal.Decimal('0.00')

val_from_db_str = format(val_from_db, 'f')
val_from_py_str = format(val_from_py, 'f')

print(val_from_db_str)
print(val_from_py_str)

assert val_from_db_str == val_from_py_str

cur.close()
con.close()

0
0.00
Traceback (most recent call last):
  File "/home/qweqq/test3.py", line 17, in <module>
    assert val_from_db_str == val_from_py_str

import decimal
print(format(decimal.Decimal('0') / 1000, 'f'))

0

import decimal
print(format(decimal.Decimal('0').scaleb(-3), 'f'))

0.000