Introduction to Python-2
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This document provides an introduction to advanced Python concepts and being "Pythonic". It discusses functions, classes, lambda functions, built-in functions like filter, map and reduce, list comprehensions, PEP (Python Enhancement Proposals), and the pip package manager. Some key Pythonic concepts covered include using built-in data types and operations like enumerate instead of range/indexing, exchanging values with a single statement instead of using a temporary variable, and joining strings with join instead of concatenation. The document aims to help readers write cleaner and more readable Python code that fully leverages the language's constructs.
![enumerate
l = [0, 1, 2, 3, 4]
for i in range(len(l)):
print i, l[i]
for i, element in enumerate(l):
print i, element](https://image.slidesharecdn.com/python-2-141228080400-conversion-gate02/85/Introduction-to-Python-2-10-320.jpg)
![string concatenating
s = “hello” + “world”
s = “”.join([“hello”, “world”])](https://image.slidesharecdn.com/python-2-141228080400-conversion-gate02/85/Introduction-to-Python-2-12-320.jpg)
![>>> a = map(lambda x : x ** 2, range(10))
>>> a = [ x ** 2 for x in range(10)]
>>> a = filter(lambda x : x % 2, range(10))
>>> a = [x for x in range(10) if x % 2]](https://image.slidesharecdn.com/python-2-141228080400-conversion-gate02/85/Introduction-to-Python-2-22-320.jpg)
![IDE
‘+’.join([ , ])](https://image.slidesharecdn.com/python-2-141228080400-conversion-gate02/85/Introduction-to-Python-2-31-320.jpg)
Introduction to Python-2
- 1. Intro to Python by Shuai Liu
- 2. agenda • History & Basics • Advanced & Be Pythonic • Awesome Python Frameworks
- 3. Advanced & Be Pythonic
- 4. Review • int & float & bool • string & list & tuple • dict • loop & branch • def methods
- 6. def foo(a, b): """My niubility methods.""" return a + b """My niubility methods.""" >>> print foo.__doc__ >>> My niubility methods.
- 7. class Person(object): """My first class""" version = 1.0 def __init__(self, name): self.name = name print "__init__ called" def get_name(self): """Return the name""" return self.name
- 8. Pythonic
- 9. –Martijn Faassen, founder of the lxml (XML library for Python) “Pythonic is to use the Python constructs and datastructures with clean, readable idioms.”
- 10. enumerate l = [0, 1, 2, 3, 4] for i in range(len(l)): print i, l[i] for i, element in enumerate(l): print i, element
- 11. value exchange temp = foo foo = bar bar = temp foo, bar = bar, foo
- 12. string concatenating s = “hello” + “world” s = “”.join([“hello”, “world”])
- 13. λ
- 14. lambda def foo(x): return x ** 2 lambda x : x ** 2 >>> a = lambda x : x ** 2 >>> a(5) >>> 25
- 15. filter & map & reduce
- 16. >>> filter(function, iterable) >>> map(function, iterable) >>> reduce(function, iterable)
- 17. filter
- 18. map
- 19. reduce
- 22. >>> a = map(lambda x : x ** 2, range(10)) >>> a = [ x ** 2 for x in range(10)] >>> a = filter(lambda x : x % 2, range(10)) >>> a = [x for x in range(10) if x % 2]
- 24. two more things…
- 25. PEP
- 26. Python Enhancement Proposals num title owner 1 PEP Purpose and Guidelines Warsaw, Hylton, Goodger, Coghlan 4 Deprecation of Standard Modules von Löwis 5 Guidelines for Language Evolution Prescod 8 Style Guide for Python Code GvR, Warsaw, Coghlan
- 27. pip
- 28. pip • A tool for installing and managing Python packages. • $ sudo pip install Requests
- 29. Resources
- 32. IDE
- 33. Summary • OO • lambda & three functions • list comprehensions • resources
- 34. Thanks