_ptcsvp | ||
.idea | ||
pytest_csv_params | ||
tests | ||
.gitignore | ||
.pylintrc | ||
.python-version | ||
LICENSE.txt | ||
poetry.lock | ||
pyproject.toml | ||
README.md |
pytest-csv-params
A pytest plugin to parametrize data-driven tests by CSV files.
Requirements
- Python 3.8, 3.9 or 3.10
- pytest >= 7.1
There's no operating system dependend code in this plugin, so it should run anywhere where pytest runs.
Installation
Simply install it with pip...
pip install pytest-csv-params
... or poetry ...
poetry add --dev pytest-csv-params
Usage: Command Line Argument
Argument | Required | Description | Example |
---|---|---|---|
--csv-params-base-dir |
no (optional) | Define a base dir for all relative-path CSV data files (since 0.1.0) | pytest --csv-params-base-dir /var/testdata |
Usage: Decorator
Simply decorate your test method with @csv_params
and the following parameters:
Parameter | Type | Description | Example |
---|---|---|---|
data_file |
str |
The CSV file to use, relative or absolute path | "/var/testdata/test1.csv" |
base_dir |
str (optional) |
Directory to look up relative CSV files (see data_file ); overrides the command line argument |
join(dirname(__file__), "assets") |
id_col |
str (optional) |
Column name of the CSV that contains test case IDs | "ID#" |
dialect |
csv.Dialect (optional) |
CSV Dialect definition (see Python CSV Documentation) | csv.excel_tab |
data_casts |
dict (optional) |
Cast Methods for the CSV Data (see "Data Casting" below) | { "a": int, "b": float } |
CSV File Lookup Order
CSV files are looked up following this rules:
- If the
data_file
parameter is an absolute path, this is used, regardless of thebase_dir
parameter or command line argument. - If the
data_file
parameter is relative:- If the
base_dir
parameter is set, the file is looked up there, regardless of the command line argument - If the
base_dir
parameter is not set (orNone
):- If the command line argument is set, the file is looked up there
- If the command line argument is not set, the file is looked up in the current working directory
- If the
Data Casting
When data is read from CSV, they are always parsed as str
. If you need them in other formats, you can set a method that should be called with the value.
These methods can also be lambdas, and are also good for further transformations.
Data Casting Example
from pytest_csv_params.decorator import csv_params
def normalize(x: str) -> str:
return x.strip().upper()
@csv_params(
data_file="/test/data.csv",
data_casts={
"col_x": normalize,
"col_y": float,
},
)
def test_something(col_x, col_y):
# Test something...
...
CSV Format
The default CSV format is:
\r\n
as line ending- All non-numeric fields are surrounded by
"
- If you need a
"
in the value, use""
(double quote) - Fields are separated by comma (
,
)
The first line must contain the row names. Row names must match the parameters of the test method (except for an ID column that is configured as such -- see id_col
decorator parameter).
Example CSV
"ID#", "part_a", "part_b", "expected_result"
"first", 1, 2, 3
"second", 3, 4, 7
"third", 10, 11, 21
Usage Example
This example uses the CSV example from above.
from pytest_csv_params.decorator import csv_params
@csv_params(
data_file="/data/test-lib/cases/addition.csv",
id_col="ID#",
data_casts={
"part_a": int,
"part_b": int,
"expected_result": int,
},
)
def test_addition(part_a, part_b, expected_result):
assert part_a + part_b == expected_result
Shorthand example (no ID col, only string values):
from pytest_csv_params.decorator import csv_params
@csv_params("/data/test-lib/cases/texts.csv")
def test_texts(text_a, text_b, text_c):
assert f"{text_a}:{text_b}" == text_c
Breaking Changes
Version 0.2.0
- The parameter order for
pytest_csv_params.decorator.csv_params
changed to allow the shorthand usage with only adata_file
as positional argument. If you used keyword arguments only (like the docs recommend), you will not run into trouble.
Contributing
Build and test
You need Poetry in order to build this project.
Tests are implemented with pytest
, and tox
is used to orchestrate them for the supported python versions.
- Checkout this repo
- Run
poetry install
- Run
poetry run tox
(for all supported python versions) orpoetry run pytest
(for your current version)
Bugs etc.
Please send your issues to csv-params_issues
(at) jued.de
. Please include the following:
- Plugin Version used
- Pytest version
- Python version with operating system
It would be great if you could include example code that clarifies your issue.
Pull Requests
Pull requests are always welcome. Since this Gitea instance is not open to public, just send an e-mail to discuss options.
Any changes that are made are to be backed by tests. Please give me a sign if you're going to break the existing API and let us discuss ways to handle that.
Quality Measures
Backed with pytest plugins:
- Pylint (static code analysis and best practises)
- black (code formatting standards)
- isort (keep imports sorted)
- Bandit (basic static security tests)
- mypy (typechecking)
Please to a complete pytest run (poetry run pytest
), and consider running it on all supported platforms with (poetry run tox
).
License
Code is under MIT license. See LICENSE.txt
for details.