Python

Transcript

2. Python 0.9.0 20 февраля 1991
3. Guido Van Rossum Google Inc.
6. Monty Python's Flying Circus
8. public class QuickSort { public static void quicksort(int array[], int left, int right) { int i = left, j = right; int pivot = array[(left + right) / 2]; do { while (array[i] < pivot) { ++i; } while (array[j] > pivot) { --j; } if (i <= j) { int temp = array[i]; array[i] = array[j]; array[j] = temp; i++; j--; } } while (i <= j); if (left < j) { quicksort(array, left, j); } if (i < right) { quicksort(array, i, right); } } }
10. def quicksort(array): if array: left = quicksort([x for x in array[1:] if x < array[0]]) right = quicksort([x for x in array[1:] if x >= array[0]]) return left + array[:1] + right return []
11. Популярность языков на GitHub JavaScript (21%) Ruby (14%) Python (8%) Java (8%) Shell (8%) PHP (7%) C (6%) C++ (4%) 0 5 10 15 20 25
12. — простота — строгость — мощь Python в Трилане
13. Python Enhancement Proposals
14. 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! The Zen of Python
15. python -c 'import this'
16. Особенности языка
17. def users(request): """Show a list of active users.""" if request.user.is_anonymous() or not request.user.is_active: raise Http404 users = User.objects.filter(is_active=True) return render(request, 'users.html', dict(users=users))
18. def users(request): """Show a list of active users.""" if request.user.is_anonymous() or not request.user.is_active: raise Http404 users = User.objects.filter(is_active=True) return render(request, 'users.html', dict(users=users)) Значащие отступы
19. def users(request): if request.user.is_anonymous() or not request.user.is_active: raise Http404 users = User.objects.filter(is_active=True) return render(request, 'users.html', dict(users=users)) Именованные аргументы
20. manage_file( '/etc/vim/vimrc', 'salt://vim/vimrc', 'root', 'root', 0644, 'jinja', ) manage_file( name='/etc/vim/vimrc', source='salt://vim/vimrc', user='root', group='root', mode=0644, template='jinja', )
21. manage_file( '/etc/vim/vimrc', 'salt://vim/vimrc', 'root', 'root', 0644, 'jinja', ) manage_file( name='/etc/vim/vimrc', source='salt://vim/vimrc', user='root', group='root', mode=0644, template='jinja', ) Так понятнее
22. def users(request): """Show a list of active users.""" if request.user.is_anonymous() or not request.user.is_active: raise Http404 users = User.objects.filter(is_active=True) return render(request, 'users.html', dict(users=users)) Логические операторы — слова (and, or, not)
23. def users(request): """Show a list of active users.""" if request.user.is_anonymous() or not request.user.is_active: raise Http404 users = User.objects.filter(is_active=True) return render(request, 'users.html', dict(users=users)) Динамическая типизация
24. def users(request): """Show a list of active users.""" if request.user.is_anonymous() or not request.user.is_active: raise Http404 users = User.objects.filter(is_active=True) return render(request, 'users.html', dict(users=users)) Строка документации
25. if 0 <= x < 10: print('x has one digit.') elif 10 <= x < 100: print('x has two digits.') else: print('x has many digits.') Условный оператор
26. False 0 '' () [] {} set() — пустая строка — пустой кортеж — пустой список — пустой словарь — пустое множество
27. Циклы for x in range(10): print(x) x = 0 while x < 1000: x += x - 3 x = 0 while True: x += x - 3 if x >= 1000: break
28. Стандартные типы данных — bool — list, tuple, range — str — bytes, bytearray, memoryview — set, frozenset — dict
29. ООП
30. class Dog: def bark(self): print('Woof!')
31. def users(request): """Show a list of active users.""" if request.user.is_anonymous() or not request.user.is_active: raise Http404 users = User.objects.filter(is_active=True) return render(request, 'users.html', dict(users=users))
32. Всё — объект
33. >>> 'Shut up and take my money'.upper() 'SHUT UP AND TAKE MY MONEY'
34. Протоколы
35. len(a) str(a) a[2] b in a a + b a.__len__() a.__str__() a.__getitem__(2) a.__contains__(b) a.__add__(b) Python
36. Зачем?
37. Python len(a)
38. Java anArray.length aString.length() aMap.size() nodeList.getLength()
40. Стандартная библиотека > 200 пакетов
41. pypi.python.org > 24 000 пакетов
42. Кто использует?
44. Как используется?
45. Веб-разработка — Django — Flask — Pyramid
46. from flask import Flask app = Flask(__name__) @app.route("/hello/") def hello(): return "Hello World!" if __name__ == "__main__": app.run() Веб-разработка
47. Работа с БД — Django ORM — SQLAlchemy — peewee
48. Разработка десктопных приложений — PySide (Qt) — PyGtk (Gtk) — WxPython (WxWidgets) — Kivy (Linux/Windows/OS X/Android/iOS)
49. Научные вычисления — NumPy — SciPy — Matplotlib
50. Где почитать?
51. docs.python.org
52. getpython3.com/diveintopython3
53. codecademy.com/tracks/python
54. twitter.com — mitsuhiko — kennethreitz — alex_gaynor — zzzeek — raymondh — tarek_ziade — voidspace — zeeg — jessenoller — nedbat
55. Изучайте новые языки
56. Python Ruby Clojure Lua JavaScript Erlang Go Rust
57. Как можно изучать на практике
58. codeforces.ru
59. codeforces.ru — C — C++ — C# — Pascal — Java — Ruby — Python — PHP — Haskell — F# — OCaml — Scala
60. spoj.pl
61. spoj.pl — C — C++ — C# — Pascal — Java — Ruby — Python — PHP — Haskell — F# — OCaml — Scala — Lua — Go — Erlang — Clojure — JavaScript — Perl
62. Численные методы