# Copyright: See the LICENSE file.
"""Additional declarations for "fuzzy" attribute definitions."""
import datetime
import decimal
import string
import warnings
from . import declarations, random
random_seed_warning = (
"Setting a specific random seed for {} can still have varying results "
"unless you also set a specific end date. For details and potential solutions "
"see https://github.com/FactoryBoy/factory_boy/issues/331"
)
[docs]class BaseFuzzyAttribute(declarations.BaseDeclaration):
"""Base class for fuzzy attributes.
Custom fuzzers should override the `fuzz()` method.
"""
[docs] def fuzz(self): # pragma: no cover
raise NotImplementedError()
def evaluate(self, instance, step, extra):
return self.fuzz()
[docs]class FuzzyAttribute(BaseFuzzyAttribute):
"""Similar to LazyAttribute, but yields random values.
Attributes:
function (callable): function taking no parameters and returning a
random value.
"""
def __init__(self, fuzzer):
super().__init__()
self.fuzzer = fuzzer
def fuzz(self):
return self.fuzzer()
[docs]class FuzzyText(BaseFuzzyAttribute):
"""Random string with a given prefix.
Generates a random string of the given length from chosen chars.
If a prefix or a suffix are supplied, they will be prepended / appended
to the generated string.
Args:
prefix (text): An optional prefix to prepend to the random string
length (int): the length of the random part
suffix (text): An optional suffix to append to the random string
chars (str list): the chars to choose from
Useful for generating unique attributes where the exact value is
not important.
"""
def __init__(self, prefix='', length=12, suffix='', chars=string.ascii_letters):
super().__init__()
self.prefix = prefix
self.suffix = suffix
self.length = length
self.chars = tuple(chars) # Unroll iterators
def fuzz(self):
chars = [random.randgen.choice(self.chars) for _i in range(self.length)]
return self.prefix + ''.join(chars) + self.suffix
[docs]class FuzzyChoice(BaseFuzzyAttribute):
"""Handles fuzzy choice of an attribute.
Args:
choices (iterable): An iterable yielding options; will only be unrolled
on the first call.
getter (callable or None): a function to parse returned values
"""
def __init__(self, choices, getter=None):
self.choices = None
self.choices_generator = choices
self.getter = getter
super().__init__()
def fuzz(self):
if self.choices is None:
self.choices = list(self.choices_generator)
value = random.randgen.choice(self.choices)
if self.getter is None:
return value
return self.getter(value)
[docs]class FuzzyInteger(BaseFuzzyAttribute):
"""Random integer within a given range."""
def __init__(self, low, high=None, step=1):
if high is None:
high = low
low = 0
self.low = low
self.high = high
self.step = step
super().__init__()
def fuzz(self):
return random.randgen.randrange(self.low, self.high + 1, self.step)
[docs]class FuzzyDecimal(BaseFuzzyAttribute):
"""Random decimal within a given range."""
def __init__(self, low, high=None, precision=2):
if high is None:
high = low
low = 0.0
self.low = low
self.high = high
self.precision = precision
super().__init__()
def fuzz(self):
base = decimal.Decimal(str(random.randgen.uniform(self.low, self.high)))
return base.quantize(decimal.Decimal(10) ** -self.precision)
[docs]class FuzzyFloat(BaseFuzzyAttribute):
"""Random float within a given range."""
def __init__(self, low, high=None, precision=15):
if high is None:
high = low
low = 0
self.low = low
self.high = high
self.precision = precision
super().__init__()
def fuzz(self):
base = random.randgen.uniform(self.low, self.high)
return float(format(base, '.%dg' % self.precision))
[docs]class FuzzyDate(BaseFuzzyAttribute):
"""Random date within a given date range."""
def __init__(self, start_date, end_date=None):
super().__init__()
if end_date is None:
if random.randgen.state_set:
cls_name = self.__class__.__name__
warnings.warn(random_seed_warning.format(cls_name), stacklevel=2)
end_date = datetime.date.today()
if start_date > end_date:
raise ValueError(
"FuzzyDate boundaries should have start <= end; got %r > %r."
% (start_date, end_date))
self.start_date = start_date.toordinal()
self.end_date = end_date.toordinal()
def fuzz(self):
return datetime.date.fromordinal(random.randgen.randint(self.start_date, self.end_date))
class BaseFuzzyDateTime(BaseFuzzyAttribute):
"""Base class for fuzzy datetime-related attributes.
Provides fuzz() computation, forcing year/month/day/hour/...
"""
def _check_bounds(self, start_dt, end_dt):
if start_dt > end_dt:
raise ValueError(
"""%s boundaries should have start <= end, got %r > %r""" % (
self.__class__.__name__, start_dt, end_dt))
def _now(self):
raise NotImplementedError()
def __init__(self, start_dt, end_dt=None,
force_year=None, force_month=None, force_day=None,
force_hour=None, force_minute=None, force_second=None,
force_microsecond=None):
super().__init__()
if end_dt is None:
if random.randgen.state_set:
cls_name = self.__class__.__name__
warnings.warn(random_seed_warning.format(cls_name), stacklevel=2)
end_dt = self._now()
self._check_bounds(start_dt, end_dt)
self.start_dt = start_dt
self.end_dt = end_dt
self.force_year = force_year
self.force_month = force_month
self.force_day = force_day
self.force_hour = force_hour
self.force_minute = force_minute
self.force_second = force_second
self.force_microsecond = force_microsecond
def fuzz(self):
delta = self.end_dt - self.start_dt
microseconds = delta.microseconds + 1000000 * (delta.seconds + (delta.days * 86400))
offset = random.randgen.randint(0, microseconds)
result = self.start_dt + datetime.timedelta(microseconds=offset)
if self.force_year is not None:
result = result.replace(year=self.force_year)
if self.force_month is not None:
result = result.replace(month=self.force_month)
if self.force_day is not None:
result = result.replace(day=self.force_day)
if self.force_hour is not None:
result = result.replace(hour=self.force_hour)
if self.force_minute is not None:
result = result.replace(minute=self.force_minute)
if self.force_second is not None:
result = result.replace(second=self.force_second)
if self.force_microsecond is not None:
result = result.replace(microsecond=self.force_microsecond)
return result
[docs]class FuzzyNaiveDateTime(BaseFuzzyDateTime):
"""Random naive datetime within a given range.
If no upper bound is given, will default to datetime.datetime.now().
"""
def _now(self):
return datetime.datetime.now()
def _check_bounds(self, start_dt, end_dt):
if start_dt.tzinfo is not None:
raise ValueError(
"FuzzyNaiveDateTime only handles naive datetimes, got start=%r"
% start_dt)
if end_dt.tzinfo is not None:
raise ValueError(
"FuzzyNaiveDateTime only handles naive datetimes, got end=%r"
% end_dt)
super()._check_bounds(start_dt, end_dt)
[docs]class FuzzyDateTime(BaseFuzzyDateTime):
"""Random timezone-aware datetime within a given range.
If no upper bound is given, will default to datetime.datetime.now()
If no timezone is given, will default to utc.
"""
def _now(self):
return datetime.datetime.now(tz=datetime.timezone.utc)
def _check_bounds(self, start_dt, end_dt):
if start_dt.tzinfo is None:
raise ValueError(
"FuzzyDateTime requires timezone-aware datetimes, got start=%r"
% start_dt)
if end_dt.tzinfo is None:
raise ValueError(
"FuzzyDateTime requires timezone-aware datetimes, got end=%r"
% end_dt)
super()._check_bounds(start_dt, end_dt)