The document discusses best practices in software engineering, specifically focusing on Python programming, testing, and performance evaluation. It emphasizes the importance of simplicity, code quality, unit testing, and effective documentation, aligning with the 'Zen of Python' principles. Various techniques for performance testing, bug tracking, and static analysis are presented, along with examples and codes to illustrate these concepts.

1. simple is better than complex
The Zen of Python (import this)
Qualidade levada a sério em Python

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• Pesquisador de segurança sênior
• Programador C/C++ e Python
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3. 5° software mais baixado
Maior empresa mobile LA
200 mil downloads/dia

5. Pessoas
Processo
Produto

6. Versionamento
Qualidade
Automatização
Requisitos
Metodologia
Processo = Engenharia de software

7. Testes
Analise estática
Bug Tracking
Documentação

11. Testes de
software

15. Específicos
Auto descritivos
Auto suficientes
Indicar o comportamento esperado
Servir de documentação
Bugs tendem a virar um caso de teste
Unit Tests

16. PyUnit
Unit Tests
assertTrue
assertEqual
assertAlmostEqual
assertIn

17. Mão na massa!

18. Test Fixture
Test Case
Test Suite
Test Runner
Unit Tests

19. Test Fixture

20. Test Fixture
class SimpleTestCase(unittest.TestCase):
def setUp(self):
"""Call before every test case.""“
self.foo = Foo()
self.file = open( "blah", "r" )
def tearDown(self):
"""Call after every test case.""“
self.file.close()

21. OQueTaSendoTestando_Parametros_RetornoEsperado
get_client_name__with_invalid__params_must_return_False
Test Case

22. def test_get_client_name__with_invalid__params_must_return_False (self):
"""Test case 1. note that all test method names must begin with 'test.'""“
self.assertEqual(foo.get_client_name(None) , False)
OQueTaSendoTestando_Parametros_RetornoEsperado
get_client_name__with_invalid__params_must_return_False

23. import unittest
from foobarbaz import Foo # code from module you're testing
class SimpleTestCase(unittest.TestCase):
def setUp(self):
"""Call before every test case.""“
self.foo = Foo()
self.file = open( "blah", "r" )
def tearDown(self):
"""Call after every test case.""“
self.file.close()
def test_get_client_name__with_invalid__params_must_return_False (self):
"""Test case 1. note that all test method names must begin with 'test.'""“
self.assertEqual(foo.get_client_name(None) , False)
Test Suite

24. Gerencia os testes e fornece uma interface de acesso.
Test Runner

26. Teste se torna o primeiro cliente do seu código
Somente o codigo necessario é criado
Erros são identificados mais rapidamente
Ganho de produtividade
Códigos entregues realmente prontos
Facilita depuração

27. Integration Tests

28. Integration Tests
def test_add_source_must_check_duplicated(self):
psw = PhishingServiceWrapper()
psw.add_url('http://www.testededominio.com.br', source_id=1)
add_ret = psw.add_url('http://www.testededominio.com.br', source_id=1)
self.assertEqual(add_ret['status'], 'duplicated')

29. Performance Tests

30. Performance Tests
__main__.SomeTest.testOne: 1.001
__main__.SomeTest.testTwo: 2.002
-----------------------------------------------
Ran 2 tests in 3.003s OK

31. Performance Tests
import cProfile
import unittest
if __name__ == '__main__':
suite = unittest.TestLoader().discover('.')
def runtests():
unittest.TextTestRunner().run(suite)
cProfile.run('runtests()',sort='cumtime')

32. Performance Tests
25510 function calls (25298 primitive calls) in 0.820 seconds
Ordered by: cumulative time
ncalls tottime percall cumtime percall filename:lineno(function)
1 0.000 0.000 0.820 0.820 <string>:1(<module>)

33. Performance Tests
def test_add_source_must_check_duplicated(self):
import time
psw = PhishingServiceWrapper()
before_functiion = time.time()
psw.add_url('http://www.testededominio.com.br', source_id=1)
after_functiion = time.time()
self.assertLess(after_functiion - before_function, 1.0)

34. Performance Tests@profile
def primes(n):
if n==2:
return [2]
elif n<2:
return []
s=range(3,n+1,2)
mroot = n ** 0.5
half=(n+1)/2-1
i=0
m=3
while m <= mroot:
if s[i]:
j=(m*m-3)/2
s[j]=0
while j<half:
s[j]=0
j+=m
i=i+1
m=2*i+3
return [2]+[x for x in s if x]
primes(100)
pip install line_profiler
kernprof -l –v primes.py

35. Performance Tests
Line # Hits Time Per Hit % Time Line Contents
==============================================================
2 @profile
3 def primes(n):
4 1 2 2.0 1.1 if n==2:
5 return [2]
6 1 1 1.0 0.5 elif n<2:
7 return []
8 1 4 4.0 2.1 s=range(3,n+1,2)
9 1 10 10.0 5.3 mroot = n ** 0.5
10 1 2 2.0 1.1 half=(n+1)/2-1
11 1 1 1.0 0.5 i=0
12 1 1 1.0 0.5 m=3
13 5 7 1.4 3.7 while m <= mroot:
14 4 4 1.0 2.1 if s[i]:
15 3 4 1.3 2.1 j=(m*m-3)/2
16 3 4 1.3 2.1 s[j]=0
17 31 31 1.0 16.3 while j<half:
18 28 28 1.0 14.7 s[j]=0
19 28 29 1.0 15.3 j+=m
20 4 4 1.0 2.1 i=i+1
21 4 4 1.0 2.1 m=2*i+3
22 50 54 1.1 28.4 return [2]+[x for x in s if x]

36. Performance Tests
python -m memory_profiler primes.py
pip install memory_profiler

37. Performance
2 @profile
3 7.9219 MB 0.0000 MB def primes(n):
4 7.9219 MB 0.0000 MB if n==2:
5 return [2]
6 7.9219 MB 0.0000 MB elif n<2:
7 return []
8 7.9219 MB 0.0000 MB s=range(3,n+1,2)
9 7.9258 MB 0.0039 MB mroot = n ** 0.5
10 7.9258 MB 0.0000 MB half=(n+1)/2-1
11 7.9258 MB 0.0000 MB i=0
12 7.9258 MB 0.0000 MB m=3
13 7.9297 MB 0.0039 MB while m <= mroot:
14 7.9297 MB 0.0000 MB if s[i]:
15 7.9297 MB 0.0000 MB j=(m*m-3)/2
16 7.9258 MB -0.0039 MB s[j]=0
17 7.9297 MB 0.0039 MB while j<half:
18 7.9297 MB 0.0000 MB s[j]=0
19 7.9297 MB 0.0000 MB j+=m
20 7.9297 MB 0.0000 MB i=i+1
21 7.9297 MB 0.0000 MB m=2*i+3
22 7.9297 MB 0.0000 MB return [2]+[x for x in s if x]

38. Bug Tracking

39. Bug Tracking
import unittest
from foobarbaz import Foo
class SimpleTestCase(unittest.TestCase):
def setUp(self):
"""Call before every test case.""“
self.foo = Foo()
self.file = open( "blah", "r" )
def tearDown(self):
"""Call after every test case.""“
self.file.close()
def test_get_client_name__with_big_param__must_return_False (self):
self.assertEqual(foo.get_client_name(“A” * 1024*1024) , False)

40. Analise estática

41. Analise estática
Checar idioma
Documentação de codigo
Compliance
Erros
Codigos duplicados ou complexos
pylint file.py
pip install pylint

42. Analise estática

43. Analise estática
radon
pip install radon
Complexidade ciclomática
Linhas de código, comentários, ...
Maintainability Index

44. Analise estática

45. Analise estática

46. Analise estática

47. Analise estática

48. Documentação
DocStrings
Documentação simples e clara, não deve conter detalhes da implementação
Documentação ruim é pior do que não documentado
Sumarizar o comportamento da função
Argumentos, retornos, exceções disparadas e restrições.
Não documentar o obvio

49. Documentação

50. import this
simple is better than complex

51. pep-0020
The Zen of Python

52. Beautiful is better than ugly.
Explicit is better than implicit.
Simple is better than complex.
Complex is better than complicated.
Flat is better than nested.
Sparse is better than dense.
Readability counts.
Special cases aren't special enough to break the rules.
Although practicality beats purity.
Errors should never pass silently.
Unless explicitly silenced.
In the face of ambiguity, refuse the temptation to guess.
There should be one-- and preferably only one --obvious way to do it.
Although that way may not be obvious at first unless you're Dutch.
Now is better than never.
Although never is often better than *right* now.
If the implementation is hard to explain, it's a bad idea.
If the implementation is easy to explain, it may be a good idea.
Namespaces are one honking great idea -- let's do more of those!

53. emiliocini@gmail.com
www.emiliosimoni.com