Menjaga paket Anda tetap rapi

Mengembangkan Paket Python

James Fulton

Climate informatics researcher

Mengenal flake8

Gaya standar Python dijelaskan di PEP8
Panduan gaya menentukan tata letak kode
pytest untuk menemukan bug
flake8 untuk menemukan kesalahan gaya

Menjalankan flake8

Pemeriksa kode statis - membaca kode tanpa menjalankannya

flake8 features.py

features.py:2:1: F401 'math' imported but unused
..

<filename>:<line number>:<charcter number>:<error code> <desciption>

Gunakan output untuk kode berkualitas

 1. import numpy as np
 2. import math
 3.
 4. def mean(x):
 5.    """Calculate the mean"""
 6.    return np.mean(x)
 7. def std(x):
 8.     """Calculate the standard deviation"""
 9.     mean_x = mean(x)
10.     std = mean((x-mean(x))**2)
11.     return std
12.

flake8 features.py

2:1: F401 'math' imported but unused

4:1: E302 expected 2 blank lines, found 1

7:1: E302 expected 2 blank lines, found 0

5:4: E111 indentation is not a multiple
     of four
6:4: E111 indentation is not a multiple
     of four

9:5: F841 local variable 'mean_x' is 
     assigned to but never used

Gunakan output untuk kode berkualitas

 1. import numpy as np
 2.
 3.
 4. def mean(x):
 5.     """Calculate the mean"""
 6.     return np.mean(x)
 7. 
 8. 
 9. def std(x):
10.     """Calculate the standard deviation"""
11.     mean_x = mean(x)
12.     std = mean((x - mean_x)**2)
13.     return std
14.

flake8 features.py

Melanggar aturan dengan sengaja

quadratic.py

4. ...
5. quadratic_1 = 6 * x**2 + 2 * x + 4;
6. quadratic_2 = 12 * x**2 + 2 * x + 8
7. ...

Melanggar aturan dengan sengaja

quadratic.py

4. ...
5. quadratic_1 =  6 * x**2 + 2 * x + 4;
6. quadratic_2 = 12 * x**2 + 2 * x + 8
7. ...

flake8 quadratic.py

quadratic.py:5:14: E222 multiple spaces after operator
quadratic.py:5:35: E703 statement ends with a semicolon

Melanggar aturan dengan sengaja

quadratic.py

4. ...
5. quadratic_1 =  6 * x**2 + 2 * x + 4; # noqa
6. quadratic_2 = 12 * x**2 + 2 * x + 8
7. ...

flake8 quadratic.py

Melanggar aturan dengan sengaja

quadratic.py

4. ...
5. quadratic_1 =  6 * x**2 + 2 * x + 4; # noqa: E222
6. quadratic_2 = 12 * x**2 + 2 * x + 8
7. ...

flake8 quadratic.py

quadratic.py:5:35: E703 statement ends with a semicolon

Pengaturan flake8

Mengabaikan pelanggaran gaya tanpa komentar

flake8 --ignore E222 quadratic.py

quadratic.py:5:35: E703 statement ends with a semicolon

flake8 --select F401,F841 features.py

2:1: F401 'math' imported but unused
9:5: F841 local variable 'mean_x' is assigned 
     to but never used

Memilih pengaturan paket dengan setup.cfg

Buat setup.cfg untuk menyimpan pengaturan

Pohon file paket

.
|-- example_package
|   |-- __init__.py
|   `-- example_package.py
|-- tests
|   |-- __init__.py
|   `-- test_example_package.py
|-- README.rst
|-- LICENSE
|-- MANIFEST.in
`-- setup.py

Memilih pengaturan paket dengan setup.cfg

Buat setup.cfg untuk menyimpan pengaturan

[flake8]


ignore = E302

exclude = setup.py


per-file-ignores =
  example_package/example_package.py: E222

Pohon file paket

.
|-- example_package
|   |-- __init__.py
|   `-- example_package.py
|-- tests
|   |-- __init__.py
|   `-- test_example_package.py
|-- README.rst
|-- LICENSE
|-- MANIFEST.in
|-- setup.py
`-- setup.cfg

Seluruh paket

$ flake8

Pohon file paket

.
|-- example_package
|   |-- __init__.py
|   `-- example_package.py
|-- tests
|   |-- __init__.py
|   `-- test_example_package.py
|-- README.rst
|-- LICENSE
|-- MANIFEST.in
|-- setup.py
`-- setup.cfg

Gunakan penyaringan seminimal mungkin

Penyaringan paling sedikit

# noqa : <code>
# noqa
setup.py → per-file-ignores
setup.cfg → exclude, ignore

Penyaringan paling banyak

Ayo berlatih!

Mengembangkan Paket Python