Cheuk Ting Ho
Developer advocate / Data Scientist - support open-source and building the community.
Generating Data Frames for your test
using Pandas stratgies in Hypothesis
Grab this slides: slides.com/cheukting_ho/hypothesis-dataframe
Hello I am Cheuk
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Open-Source contributor
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Organisers of community events
-
PSF director and fellow
- Community manager at OpenSSF
- Part of the Linux Foundation
- Focus on Open Source Security
- Not for Profit
- Security newsletters and blog
- Free courses:
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OpenSSF Day (OSS EU)
- 18th Spet Bilbao
Who is familiar with Property based testing?
Property
- the given is obvious
- works extra well with typing
- edge case automatically be found
Example
- need to think of what is and what is not
- take extra steps to write examples
- may overlook edge cases
Testing by...
import pytest
@pytest.mark.parametrize("s", ["", "something", "12345"])
def test_decode_inverts_encode(s):
assert decode(encode(s)) == sTest by example
from hypothesis import given
from hypothesis.strategies import text
@given(text())
def test_decode_inverts_encode(s):
assert decode(encode(s)) == sTest by property
How does Hypothesis do it?
decorators
entry point to modify the test
strategies
generating test data
Core strategies
- binary
- booleans
- characters
- complex_numbers
- dates
- datetimes
- decimals
- emails
- floats
- fractions
- from_regex
- integers
- ip_addresses
- none
- text
- timedeltas
- times
- timezones
- uuids
Combine / Build your strategies
- lists
- dictionaries
- one_of
- builds
Do you know the component of a pandas DataFrame?
Pandas strategies
- series
- column
- data_frames
Numpy strategies
- arrays
- array_shapes
Generating Data Frames for your test
By Cheuk Ting Ho
