Python core

1. REPL: Read, Evaluate, Print, Loop

2. int REPL, type _ to most recently printed value, only in REPL

3. 在REPL里输入多行：

 

4. PEPs: Python Enhancement Proposals

 

5. Zen of Python

 

6. import a library and use help to show the functions in the library, type q to quit the help and return to REPL

 

 7. 给函数起个别名

 

 8. / and //

 

9. type int: unlimited precision signed integer

 

 int函数的第二个参数是进制，比如上面的例子，3表示3进制，10表示10进制

 10. float type: IEEE-754 double-precision with 53-bits of binary precision, 15-16 significant digits in decimal

 

 11. None value

 12. Boolen value

 13. Relational Operators

 

 14. Control Flow

 15. while and break

 16. Augmented (增强) assignment operators: -=, +=

 17. str

 

 18. Universal Newlines: Python translates \n to the appropriate newline sequence for your platform

PEP 278

19. Escape character \

 

 

 20. create a row string with prefix r

 

 21. convert from int or float to str use str(), Strings in python are called sequence types

 

 22. str functions

 23. unicode

 

 

24. Bytes: 与str类似，但是是单字节的

 

 

25. Convert with encode and decode

 

 

 26. list

 27. dict, Map keys to values

 

28. for loop

 29. example of read data from url

 30. 执行一个python文件

 

 import一个文件

 

 31. define a function

 

 32: dunder: instead of "underscore underscore name underscore underscore" we say "dunder name", __name__

 33. import a module and run a function, 注意：import只会被执行一次

 34. import a function only

 

 35. __name__，可以区分modle是在被引用，还是被脚本执行

 

 

 

 

 

 如果是在脚本中运行，就执行函数

 36. import

 

 

 

 37. use command argument

  

 

 38. docstring

 

 

 

 

 

 add more docstring

 

 

 

 39. run .py file directly, which called Shebang in linux

 

 

 40. id()

 

 

 

 41.

 42. == and is, == means same value

 

 

 

 43. pass parameter to function, 感觉像传的引用

 

 

 

 

 

 

 

 

 

 

 44. Default argument values

 

 

45. Default argument 的值没有变，因为default value只在def被执行时运行一次，所以不要使用会变的default value

 

 

 

 46. Modifying Mutable Default values

 

 

 

 

workaround of above example

 

 

 47. dynamic types

 

 48.

 

 

 49. Scopes in python

 

 

50. rebinding global names

 

 

 

 51. everything is object

 52. tuple: Immutable sequences of arbitrary objects

 

 53. return a tuple

 54. tuple unpacking

 

 

 

 

 

55. convert to tuple use tuple(), and test if element in the tuple

 

 56. string

 

 57. join

 

 

 

 58. partition

 

 有的系统里会使用_来保存分隔符，使用_的好处是可以避免variable not used的警告

 59. string format

 

 60. f-string

 

 

 61. range

 

 62

 

 

 63. list

 

 64. copy list, all of these techniques perform shallow copies. 对象里的子对象还是只是copy了引用

 

 

 

 

 65. 复制list中的子项

 

 66. index

 

 67. delete element from list

 68. insert element

 

 69. 一些操作

 

 70. reverse and sort

 

 

 71. reverse and sort with copy

 

72. Dictionaries

 

 

 

 73. create dictionary

 

 74. copy dictionary

 

 75. dictionary update

 76. dictionary iteration

 

 by value

 

 by key

 

每个item都是一个tuple

 

 

 77. in and out

 

 78. delete element

 

 79. update element

 

 80. 使用pprint更好的显示

 81. set

 

 

 

 set会删除冗余项

 

 82. set 中item的顺序是任意的

 

 83. in and not in also working for set

 

 84. add and update set

 

 85. remove and discard

 

 86. copy a set

 87. Set Algebra

 

 

 

 

 

 

 

88. 没有同时出现在两个set里

 

 

89. subset, superset or 没有交集

 

 90. Protocols

 

 

 91. exception

 

 

 

 92. example to cause exception

 

 

 

 93. add exception handling

 

 

 

 another exception

 

 make update

 

 

 

 updated version

 因为block不允许为空，所以可以用pass作为占位符

 update again

 

 

 

 94. Re-raising Exceptions

 

 

 

 

 

 

 95. example to calculate sqrt

 

 

 

 96. cause a exception and handle it

 

 

 97. 

 

 

 

 

 

 98. Exceptions and protocols

 

 

99. common exception

 

 

 

 

 

 100. LBYL vs. EAFP

 

 

 

use EAFP  

 101. use finally:

 

 

 102: 捕获每一次按键和平台相关