Hypothesis is a Python library for property-based testing; creating unit tests with pseudo-randomly generated data.
Questions about the testing library Hypothesis:
Questions tagged [python-hypothesis]
182 questions
0
votes
1 answer
How to combine the @fixture and the @given decorators in Python hypothesis testing?
I'm working with pytest and hypothesis for property-based testing in Python.
As a minimal example, suppose I want to test that my Matrix class constructor correctly assign the number of rows and columns to a Matrix instance. I want to do it in two…
SimoneGasperini
- 113
- 5
0
votes
2 answers
How to make custom Hypothesis strategy to supply custom objects?
Suppose I have a class Thing
class Thing:
def __init__(self, x, y):
...
And suppose I have a function which acts on a list of things.
def do_stuff(list_of_things):
...
I would like to write unit tests for do_stuff involving…
Galen
- 1,128
- 1
- 14
- 31
0
votes
1 answer
Create a pd.DataFrame with a minimum number of rows using hypothesis
I'm using the hypothesis library and I would like to create a pd.DataFrame with three columns. Each column may contain integer values, either +1, 0, or -1. The values doesn't need to be unique. Also, I would like to get at least ten rows.
With the…
Andi
- 3,196
- 2
- 24
- 44
0
votes
1 answer
Generating an interval set in hypothesis
I have some code that works with intervals, which are really just python dicts with the following structure:
{
"name": "some utf8 string",
"start": 0.0, # 0.0 <= start < 1.0
"end": 1.0, # start < end <= 1.0
"size": 1.0, # size…
breadjesus
- 1,979
- 3
- 13
- 8
0
votes
1 answer
How to generate complex Hypothesis data frames with internal row and column dependencies?
Is there an elegant way of using hypothesis to directly generate complex pandas data frames with internal row and column dependencies? Let's say I want columns such…
curlew77
- 393
- 5
- 15
0
votes
1 answer
How can I generate instances of a class with inter-dependent attributes?
Assume this simple case: (reposted and lightly edited from the Hypothesis mailing list)
@dataclass
class A:
names: list[str]
ages: dict[str, float]
How could I write a strategy which generates objects of type A but with the restriction that…
Zac Hatfield-Dodds
- 2,455
- 6
- 19
0
votes
1 answer
Why use recursive() instead of deferred()?
I needed a strategy for arbitrary JSON values and after reading about the gotchas of using composite() for recursive data came up with this
json_primitives = st.one_of(
st.none(),
st.booleans(),
st.integers(),
…
Chris Wesseling
- 6,226
- 2
- 36
- 72
0
votes
1 answer
Hypothesis, using "one_of" with Pandas dtypes in the "data_frames" strategy
I would like to construct a Pandas series that is any of several dtypes.
I was hoping to do something like this:
from hypothesis import given
import hypothesis.strategies as hs
import hypothesis.extra.numpy as hs_np
import hypothesis.extra.pandas as…
shadowtalker
- 12,529
- 3
- 53
- 96
0
votes
1 answer
Hypothesis strategy from_regex does not respect min_size and max_size
I am having issues with Hypothesis generating strings which do not respect the given min/max sizes. Example:
@given(
st.text(
alphabet=st.from_regex(regex=r"^[a-z][b-z]$", fullmatch=True),
min_size=0,
max_size=15,
…
damd
- 6,116
- 7
- 48
- 77
0
votes
1 answer
Randomizing a user dataclass with pytest and hypothesis
I can manually define an Address builder strategy:
import attrs
from hypothesis import given
import hypothesis.strategies as st
@attrs.frozen(kw_only=True)
class Address:
street: str
city: str
AddressStrategy = st.builds(
Address,
…
OrenIshShalom
- 5,974
- 9
- 37
- 87
0
votes
1 answer
Create hypothesis strategy that returns unique values
I'm trying to create a hypothesis strategy which produces integers with no repeats. Here's my code:
import hypothesis
import hypothesis.strategies as strategies
def unique(strat):
previous = set()
@strategies.composite
def…
Daniel Walker
- 6,380
- 5
- 22
- 45
0
votes
1 answer
Hypothesis python package for onehots and longitudinal data
For context I work with mixed tabular data. I have complex data pipelines that I’d like to make sure works on any configuration of data.
I see the pandas add-on/extra and have some questions related to that.
How would I generate one-hot columns…
davzaman
- 823
- 2
- 10
- 20
0
votes
1 answer
taking square using "value**2" results causes an overflow while "value*value" is fine
Given the same input, x**2 gives an integer overflow while x*x works fine.
I am not sure if this is because of the python's internal implementation of those operator or if this is a bug in the hypothesis package. Is the opcode for x**2 different…
anilbey
- 1,817
- 4
- 22
- 38
0
votes
1 answer
How to check internal size parameters that controls example generation
In PropEr, there's an internal variable called Size that represents the size of generated example.
For instance, when we have 2 variables and would like to make them proportional each other, PropEr let you write the following test:
prop_profile2()…
Yoshi
- 405
- 4
- 12
0
votes
1 answer
`event` throws TypeError caused by WeakKeyDictionary when tuple is passed
I wanted to see the statistics of list values and I passed the value to event() after converting it to tuple to make it hashable.
@dataclass(frozen=True)
class Foo:
x: int
y: str
def __hash__(self):
return hash((self.x,…
Yoshi
- 405
- 4
- 12