Python从入门到精通_第1课_入门基础_笔记

Dear 丶 2021-11-17 23:16 427阅读 0赞

文章目录

  • Python简介
  • 为什么选择Python
  • 环境搭建
  • 如何学好编程
  • 常用关键字
  • 基本运算符
  • 基本语法

GitHub: https://github.com/RealEmperor/Basic-Introductory-Python-Course

Python简介

Python 是一种易于学习又功能强大的编程语言。它提供了高效的高级数据结构，还有简单有效的面向对象编程。Python 优雅的语法和动态类型，以及解释型语言的本质，使它成为多数平台上写脚本和快速开发应用的理想语言。

Python 解释器及丰富的标准库以源码或机器码的形式提供，可以到 Python 官网 https://www.python.org/ 免费获取适用于各个主要系统平台的版本，并可自由地分发。这个网站还包含许多免费第三方 Python 模块、程序和工具以及附加文档的发布页面或链接。

Python 解释器易于扩展，可以使用 C 或 C++（或者其他可以通过 C 调用的语言）扩展新的功能和数据类型。Python 也可用于可定制化软件中的扩展程序语言。
来源：https://docs.python.org/zh-cn/3/tutorial/index.html

为什么选择Python

Python很强大（略）

环境搭建

推荐使用安装Anaconda,大部分我们要用到的库都有了，官网：https://www.anaconda.com/

IDE推荐使用PyCharm，具体的安装办法网上很多。

如何学好编程

仁者见仁智者见智，多看，多写

最新的Python中文文档在这里：
https://docs.python.org/zh-cn/3/

常用关键字

  1. help("keywords")
  3. Here is a list of the Python keywords.  Enter any keyword to get more help.
  5. False               def                 if                  raise
  6. None                del                 import              return
  7. True                elif                in                  try
  8. and                 else                is                  while
  9. as                  except              lambda              with
  10. assert              finally             nonlocal            yield
  11. break               for                 not                 
  12. class               from                or                  
  13. continue            global              pass

help([object])
启动内置的帮助系统（此函数主要在交互式中使用）。如果没有实参，解释器控制台里会启动交互式帮助系统。如果实参是一个字符串，则在模块、函数、类、方法、关键字或文档主题中搜索该字符串，并在控制台上打印帮助信息。如果实参是其他任意对象，则会生成该对象的帮助页。
来源：https://docs.python.org/zh-cn/3/library/functions.html#help

  1. # help的更多例子：
  2. # 查看Python所有的modules：
  3. help('modules')
  5. # 查看Python中的topics：
  6. help('topics')
  8. Here is a list of available topics.  Enter any topic name to get more help.
  10. ASSERTION           DELETION            LOOPING             SHIFTING
  11. ASSIGNMENT          DICTIONARIES        MAPPINGMETHODS      SLICINGS
  12. ATTRIBUTEMETHODS    DICTIONARYLITERALS  MAPPINGS            SPECIALATTRIBUTES
  13. ATTRIBUTES          DYNAMICFEATURES     METHODS             SPECIALIDENTIFIERS
  14. AUGMENTEDASSIGNMENT ELLIPSIS            MODULES             SPECIALMETHODS
  15. BASICMETHODS        EXCEPTIONS          NAMESPACES          STRINGMETHODS
  16. BINARY              EXECUTION           NONE                STRINGS
  17. BITWISE             EXPRESSIONS         NUMBERMETHODS       SUBSCRIPTS
  18. BOOLEAN             FLOAT               NUMBERS             TRACEBACKS
  19. CALLABLEMETHODS     FORMATTING          OBJECTS             TRUTHVALUE
  20. CALLS               FRAMEOBJECTS        OPERATORS           TUPLELITERALS
  21. CLASSES             FRAMES              PACKAGES            TUPLES
  22. CODEOBJECTS         FUNCTIONS           POWER               TYPEOBJECTS
  23. COMPARISON          IDENTIFIERS         PRECEDENCE          TYPES
  24. COMPLEX             IMPORTING           PRIVATENAMES        UNARY
  25. CONDITIONAL         INTEGER             RETURNING           UNICODE
  26. CONTEXTMANAGERS     LISTLITERALS        SCOPING             
  27. CONVERSIONS         LISTS               SEQUENCEMETHODS     
  28. DEBUGGING           LITERALS            SEQUENCES
  30. # 查看Python所有的modules中包含指定字符串的modules：
  31. help("modules zlib")
  33. Here is a list of modules whose name or summary contains 'zlib'.
  34. If there are any, enter a module name to get more help.
  36. zlib - The functions in this module allow compression and decompression using the
  37. encodings.zlib_codec - Python 'zlib_codec' Codec - zlib compression encoding.
  38. test.test_zlib
  40. # 查看Python库中的module：
  41. import time
  42. help(time)
  44. Help on built-in module time:
  46. NAME
  47.     time - This module provides various functions to manipulate time values.
  49. DESCRIPTION
  50.     There are two standard representations of time.  One is the number
  51.     of seconds since the Epoch, in UTC (a.k.a. GMT).  It may be an integer
  52.     or a floating point number (to represent fractions of seconds).
  53.     The Epoch is system-defined; on Unix, it is generally January 1st, 1970.
  54.     The actual value can be retrieved by calling gmtime(0).
  56.     The other representation is a tuple of 9 integers giving local time.
  57.     The tuple items are:
  58.       year (including century, e.g. 1998)
  59.       month (1-12)
  60.       day (1-31)
  61.       hours (0-23)
  62.       minutes (0-59)
  63.       seconds (0-59)
  64.       weekday (0-6, Monday is 0)
  65.       Julian day (day in the year, 1-366)
  66.       DST (Daylight Savings Time) flag (-1, 0 or 1)
  67.     If the DST flag is 0, the time is given in the regular time zone;
  68.     if it is 1, the time is given in the DST time zone;
  69.     if it is -1, mktime() should guess based on the date and time.
  71.     Variables:
  73.     timezone -- difference in seconds between UTC and local standard time
  74.     altzone -- difference in  seconds between UTC and local DST time
  75.     daylight -- whether local time should reflect DST
  76.     tzname -- tuple of (standard time zone name, DST time zone name)
  78.     Functions:
  80.     time() -- return current time in seconds since the Epoch as a float
  81.     clock() -- return CPU time since process start as a float
  82.     sleep() -- delay for a number of seconds given as a float
  83.     gmtime() -- convert seconds since Epoch to UTC tuple
  84.     localtime() -- convert seconds since Epoch to local time tuple
  85.     asctime() -- convert time tuple to string
  86.     ctime() -- convert time in seconds to string
  87.     mktime() -- convert local time tuple to seconds since Epoch
  88.     strftime() -- convert time tuple to string according to format specification
  89.     strptime() -- parse string to time tuple according to format specification
  90.     tzset() -- change the local timezone
  92. CLASSES
  93.     builtins.tuple(builtins.object)
  94.         struct_time
  96.     class struct_time(builtins.tuple)
  97.      |  The time value as returned by gmtime(), localtime(), and strptime(), and
  98.      |  accepted by asctime(), mktime() and strftime().  May be considered as a
  99.      |  sequence of 9 integers.
  100.      |  
  101.      |  Note that several fields' values are not the same as those defined by
  102.      |  the C language standard for struct tm.  For example, the value of the
  103.      |  field tm_year is the actual year, not year - 1900.  See individual
  104.      |  fields' descriptions for details.
  105.      |  
  106.      |  Method resolution order:
  107.      |      struct_time
  108.      |      builtins.tuple
  109.      |      builtins.object
  110.      |  
  111.      |  Methods defined here:
  112.      |  
  113.      |  __new__(*args, **kwargs) from builtins.type
  114.      |      Create and return a new object.  See help(type) for accurate signature.
  115.      |  
  116.      |  __reduce__(...)
  117.      |      helper for pickle
  118.      |  
  119.      |  __repr__(self, /)
  120.      |      Return repr(self).
  121.      |  
  122.      |  ----------------------------------------------------------------------
  123.      |  Data descriptors defined here:
  124.      |  
  125.      |  tm_gmtoff
  126.      |      offset from UTC in seconds
  127.      |  
  128.      |  tm_hour
  129.      |      hours, range [0, 23]
  130.      |  
  131.      |  tm_isdst
  132.      |      1 if summer time is in effect, 0 if not, and -1 if unknown
  133.      |  
  134.      |  tm_mday
  135.      |      day of month, range [1, 31]
  136.      |  
  137.      |  tm_min
  138.      |      minutes, range [0, 59]
  139.      |  
  140.      |  tm_mon
  141.      |      month of year, range [1, 12]
  142.      |  
  143.      |  tm_sec
  144.      |      seconds, range [0, 61])
  145.      |  
  146.      |  tm_wday
  147.      |      day of week, range [0, 6], Monday is 0
  148.      |  
  149.      |  tm_yday
  150.      |      day of year, range [1, 366]
  151.      |  
  152.      |  tm_year
  153.      |      year, for example, 1993
  154.      |  
  155.      |  tm_zone
  156.      |      abbreviation of timezone name
  157.      |  
  158.      |  ----------------------------------------------------------------------
  159.      |  Data and other attributes defined here:
  160.      |  
  161.      |  n_fields = 11
  162.      |  
  163.      |  n_sequence_fields = 9
  164.      |  
  165.      |  n_unnamed_fields = 0
  166.      |  
  167.      |  ----------------------------------------------------------------------
  168.      |  Methods inherited from builtins.tuple:
  169.      |  
  170.      |  __add__(self, value, /)
  171.      |      Return self+value.
  172.      |  
  173.      |  __contains__(self, key, /)
  174.      |      Return key in self.
  175.      |  
  176.      |  __eq__(self, value, /)
  177.      |      Return self==value.
  178.      |  
  179.      |  __ge__(self, value, /)
  180.      |      Return self>=value.
  181.      |  
  182.      |  __getattribute__(self, name, /)
  183.      |      Return getattr(self, name).
  184.      |  
  185.      |  __getitem__(self, key, /)
  186.      |      Return self[key].
  187.      |  
  188.      |  __getnewargs__(...)
  189.      |  
  190.      |  __gt__(self, value, /)
  191.      |      Return self>value.
  192.      |  
  193.      |  __hash__(self, /)
  194.      |      Return hash(self).
  195.      |  
  196.      |  __iter__(self, /)
  197.      |      Implement iter(self).
  198.      |  
  199.      |  __le__(self, value, /)
  200.      |      Return self<=value.
  201.      |  
  202.      |  __len__(self, /)
  203.      |      Return len(self).
  204.      |  
  205.      |  __lt__(self, value, /)
  206.      |      Return self<value.
  207.      |  
  208.      |  __mul__(self, value, /)
  209.      |      Return self*value.n
  210.      |  
  211.      |  __ne__(self, value, /)
  212.      |      Return self!=value.
  213.      |  
  214.      |  __rmul__(self, value, /)
  215.      |      Return self*value.
  216.      |  
  217.      |  count(...)
  218.      |      T.count(value) -> integer -- return number of occurrences of value
  219.      |  
  220.      |  index(...)
  221.      |      T.index(value, [start, [stop]]) -> integer -- return first index of value.
  222.      |      Raises ValueError if the value is not present.
  224. FUNCTIONS
  225.     asctime(...)
  226.         asctime([tuple]) -> string
  228.         Convert a time tuple to a string, e.g. 'Sat Jun 06 16:26:11 1998'.
  229.         When the time tuple is not present, current time as returned by localtime()
  230.         is used.
  232.     clock(...)
  233.         clock() -> floating point number
  235.         Return the CPU time or real time since the start of the process or since
  236.         the first call to clock().  This has as much precision as the system
  237.         records.
  239.     ctime(...)
  240.         ctime(seconds) -> string
  242.         Convert a time in seconds since the Epoch to a string in local time.
  243.         This is equivalent to asctime(localtime(seconds)). When the time tuple is
  244.         not present, current time as returned by localtime() is used.
  246.     get_clock_info(...)
  247.         get_clock_info(name: str) -> dict
  249.         Get information of the specified clock.
  251.     gmtime(...)
  252.         gmtime([seconds]) -> (tm_year, tm_mon, tm_mday, tm_hour, tm_min,
  253.                                tm_sec, tm_wday, tm_yday, tm_isdst)
  255.         Convert seconds since the Epoch to a time tuple expressing UTC (a.k.a.
  256.         GMT).  When 'seconds' is not passed in, convert the current time instead.
  258.         If the platform supports the tm_gmtoff and tm_zone, they are available as
  259.         attributes only.
  261.     localtime(...)
  262.         localtime([seconds]) -> (tm_year,tm_mon,tm_mday,tm_hour,tm_min,
  263.                                   tm_sec,tm_wday,tm_yday,tm_isdst)
  265.         Convert seconds since the Epoch to a time tuple expressing local time.
  266.         When 'seconds' is not passed in, convert the current time instead.
  268.     mktime(...)
  269.         mktime(tuple) -> floating point number
  271.         Convert a time tuple in local time to seconds since the Epoch.
  272.         Note that mktime(gmtime(0)) will not generally return zero for most
  273.         time zones; instead the returned value will either be equal to that
  274.         of the timezone or altzone attributes on the time module.
  276.     monotonic(...)
  277.         monotonic() -> float
  279.         Monotonic clock, cannot go backward.
  281.     perf_counter(...)
  282.         perf_counter() -> float
  284.         Performance counter for benchmarking.
  286.     process_time(...)
  287.         process_time() -> float
  289.         Process time for profiling: sum of the kernel and user-space CPU time.
  291.     sleep(...)
  292.         sleep(seconds)
  294.         Delay execution for a given number of seconds.  The argument may be
  295.         a floating point number for subsecond precision.
  297.     strftime(...)
  298.         strftime(format[, tuple]) -> string
  300.         Convert a time tuple to a string according to a format specification.
  301.         See the library reference manual for formatting codes. When the time tuple
  302.         is not present, current time as returned by localtime() is used.
  304.         Commonly used format codes:
  306.         %Y  Year with century as a decimal number.
  307.         %m  Month as a decimal number [01,12].
  308.         %d  Day of the month as a decimal number [01,31].
  309.         %H  Hour (24-hour clock) as a decimal number [00,23].
  310.         %M  Minute as a decimal number [00,59].
  311.         %S  Second as a decimal number [00,61].
  312.         %z  Time zone offset from UTC.
  313.         %a  Locale's abbreviated weekday name.
  314.         %A  Locale's full weekday name.
  315.         %b  Locale's abbreviated month name.
  316.         %B  Locale's full month name.
  317.         %c  Locale's appropriate date and time representation.
  318.         %I  Hour (12-hour clock) as a decimal number [01,12].
  319.         %p  Locale's equivalent of either AM or PM.
  321.         Other codes may be available on your platform.  See documentation for
  322.         the C library strftime function.
  324.     strptime(...)
  325.         strptime(string, format) -> struct_time
  327.         Parse a string to a time tuple according to a format specification.
  328.         See the library reference manual for formatting codes (same as
  329.         strftime()).
  331.         Commonly used format codes:
  333.         %Y  Year with century as a decimal number.
  334.         %m  Month as a decimal number [01,12].
  335.         %d  Day of the month as a decimal number [01,31].
  336.         %H  Hour (24-hour clock) as a decimal number [00,23].
  337.         %M  Minute as a decimal number [00,59].
  338.         %S  Second as a decimal number [00,61].
  339.         %z  Time zone offset from UTC.
  340.         %a  Locale's abbreviated weekday name.
  341.         %A  Locale's full weekday name.
  342.         %b  Locale's abbreviated month name.
  343.         %B  Locale's full month name.
  344.         %c  Locale's appropriate date and time representation.
  345.         %I  Hour (12-hour clock) as a decimal number [01,12].
  346.         %p  Locale's equivalent of either AM or PM.
  348.         Other codes may be available on your platform.  See documentation for
  349.         the C library strftime function.
  351.     time(...)
  352.         time() -> floating point number
  354.         Return the current time in seconds since the Epoch.
  355.         Fractions of a second may be present if the system clock provides them.
  357. DATA
  358.     altzone = -32400
  359.     daylight = 0
  360.     timezone = -28800
  361.     tzname = ('Öйú±ê׼ʱ¼ä', 'ÖйúÏÄÁîʱ')
  363. FILE
  364.     (built-in)
  366. help('time')  # 字符串和上面效果一致
  368. Help on built-in module time:
  370. NAME
  371.     time - This module provides various functions to manipulate time values.
  373. DESCRIPTION
  374.     There are two standard representations of time.  One is the number
  375.     of seconds since the Epoch, in UTC (a.k.a. GMT).  It may be an integer
  376.     or a floating point number (to represent fractions of seconds).
  377.     The Epoch is system-defined; on Unix, it is generally January 1st, 1970.
  378.     The actual value can be retrieved by calling gmtime(0).
  380.     The other representation is a tuple of 9 integers giving local time.
  381.     The tuple items are:
  382.       year (including century, e.g. 1998)
  383.       month (1-12)
  384.       day (1-31)
  385.       hours (0-23)
  386.       minutes (0-59)
  387.       seconds (0-59)
  388.       weekday (0-6, Monday is 0)
  389.       Julian day (day in the year, 1-366)
  390.       DST (Daylight Savings Time) flag (-1, 0 or 1)
  391.     If the DST flag is 0, the time is given in the regular time zone;
  392.     if it is 1, the time is given in the DST time zone;
  393.     if it is -1, mktime() should guess based on the date and time.
  395.     Variables:
  397.     timezone -- difference in seconds between UTC and local standard time
  398.     altzone -- difference in  seconds between UTC and local DST time
  399.     daylight -- whether local time should reflect DST
  400.     tzname -- tuple of (standard time zone name, DST time zone name)
  402.     Functions:
  404.     time() -- return current time in seconds since the Epoch as a float
  405.     clock() -- return CPU time since process start as a float
  406.     sleep() -- delay for a number of seconds given as a float
  407.     gmtime() -- convert seconds since Epoch to UTC tuple
  408.     localtime() -- convert seconds since Epoch to local time tuple
  409.     asctime() -- convert time tuple to string
  410.     ctime() -- convert time in seconds to string
  411.     mktime() -- convert local time tuple to seconds since Epoch
  412.     strftime() -- convert time tuple to string according to format specification
  413.     strptime() -- parse string to time tuple according to format specification
  414.     tzset() -- change the local timezone
  416. CLASSES
  417.     builtins.tuple(builtins.object)
  418.         struct_time
  420.     class struct_time(builtins.tuple)
  421.      |  The time value as returned by gmtime(), localtime(), and strptime(), and
  422.      |  accepted by asctime(), mktime() and strftime().  May be considered as a
  423.      |  sequence of 9 integers.
  424.      |  
  425.      |  Note that several fields' values are not the same as those defined by
  426.      |  the C language standard for struct tm.  For example, the value of the
  427.      |  field tm_year is the actual year, not year - 1900.  See individual
  428.      |  fields' descriptions for details.
  429.      |  
  430.      |  Method resolution order:
  431.      |      struct_time
  432.      |      builtins.tuple
  433.      |      builtins.object
  434.      |  
  435.      |  Methods defined here:
  436.      |  
  437.      |  __new__(*args, **kwargs) from builtins.type
  438.      |      Create and return a new object.  See help(type) for accurate signature.
  439.      |  
  440.      |  __reduce__(...)
  441.      |      helper for pickle
  442.      |  
  443.      |  __repr__(self, /)
  444.      |      Return repr(self).
  445.      |  
  446.      |  ----------------------------------------------------------------------
  447.      |  Data descriptors defined here:
  448.      |  
  449.      |  tm_gmtoff
  450.      |      offset from UTC in seconds
  451.      |  
  452.      |  tm_hour
  453.      |      hours, range [0, 23]
  454.      |  
  455.      |  tm_isdst
  456.      |      1 if summer time is in effect, 0 if not, and -1 if unknown
  457.      |  
  458.      |  tm_mday
  459.      |      day of month, range [1, 31]
  460.      |  
  461.      |  tm_min
  462.      |      minutes, range [0, 59]
  463.      |  
  464.      |  tm_mon
  465.      |      month of year, range [1, 12]
  466.      |  
  467.      |  tm_sec
  468.      |      seconds, range [0, 61])
  469.      |  
  470.      |  tm_wday
  471.      |      day of week, range [0, 6], Monday is 0
  472.      |  
  473.      |  tm_yday
  474.      |      day of year, range [1, 366]
  475.      |  
  476.      |  tm_year
  477.      |      year, for example, 1993
  478.      |  
  479.      |  tm_zone
  480.      |      abbreviation of timezone name
  481.      |  
  482.      |  ----------------------------------------------------------------------
  483.      |  Data and other attributes defined here:
  484.      |  
  485.      |  n_fields = 11
  486.      |  
  487.      |  n_sequence_fields = 9
  488.      |  
  489.      |  n_unnamed_fields = 0
  490.      |  
  491.      |  ----------------------------------------------------------------------
  492.      |  Methods inherited from builtins.tuple:
  493.      |  
  494.      |  __add__(self, value, /)
  495.      |      Return self+value.
  496.      |  
  497.      |  __contains__(self, key, /)
  498.      |      Return key in self.
  499.      |  
  500.      |  __eq__(self, value, /)
  501.      |      Return self==value.
  502.      |  
  503.      |  __ge__(self, value, /)
  504.      |      Return self>=value.
  505.      |  
  506.      |  __getattribute__(self, name, /)
  507.      |      Return getattr(self, name).
  508.      |  
  509.      |  __getitem__(self, key, /)
  510.      |      Return self[key].
  511.      |  
  512.      |  __getnewargs__(...)
  513.      |  
  514.      |  __gt__(self, value, /)
  515.      |      Return self>value.
  516.      |  
  517.      |  __hash__(self, /)
  518.      |      Return hash(self).
  519.      |  
  520.      |  __iter__(self, /)
  521.      |      Implement iter(self).
  522.      |  
  523.      |  __le__(self, value, /)
  524.      |      Return self<=value.
  525.      |  
  526.      |  __len__(self, /)
  527.      |      Return len(self).
  528.      |  
  529.      |  __lt__(self, value, /)
  530.      |      Return self<value.
  531.      |  
  532.      |  __mul__(self, value, /)
  533.      |      Return self*value.n
  534.      |  
  535.      |  __ne__(self, value, /)
  536.      |      Return self!=value.
  537.      |  
  538.      |  __rmul__(self, value, /)
  539.      |      Return self*value.
  540.      |  
  541.      |  count(...)
  542.      |      T.count(value) -> integer -- return number of occurrences of value
  543.      |  
  544.      |  index(...)
  545.      |      T.index(value, [start, [stop]]) -> integer -- return first index of value.
  546.      |      Raises ValueError if the value is not present.
  548. FUNCTIONS
  549.     asctime(...)
  550.         asctime([tuple]) -> string
  552.         Convert a time tuple to a string, e.g. 'Sat Jun 06 16:26:11 1998'.
  553.         When the time tuple is not present, current time as returned by localtime()
  554.         is used.
  556.     clock(...)
  557.         clock() -> floating point number
  559.         Return the CPU time or real time since the start of the process or since
  560.         the first call to clock().  This has as much precision as the system
  561.         records.
  563.     ctime(...)
  564.         ctime(seconds) -> string
  566.         Convert a time in seconds since the Epoch to a string in local time.
  567.         This is equivalent to asctime(localtime(seconds)). When the time tuple is
  568.         not present, current time as returned by localtime() is used.
  570.     get_clock_info(...)
  571.         get_clock_info(name: str) -> dict
  573.         Get information of the specified clock.
  575.     gmtime(...)
  576.         gmtime([seconds]) -> (tm_year, tm_mon, tm_mday, tm_hour, tm_min,
  577.                                tm_sec, tm_wday, tm_yday, tm_isdst)
  579.         Convert seconds since the Epoch to a time tuple expressing UTC (a.k.a.
  580.         GMT).  When 'seconds' is not passed in, convert the current time instead.
  582.         If the platform supports the tm_gmtoff and tm_zone, they are available as
  583.         attributes only.
  585.     localtime(...)
  586.         localtime([seconds]) -> (tm_year,tm_mon,tm_mday,tm_hour,tm_min,
  587.                                   tm_sec,tm_wday,tm_yday,tm_isdst)
  589.         Convert seconds since the Epoch to a time tuple expressing local time.
  590.         When 'seconds' is not passed in, convert the current time instead.
  592.     mktime(...)
  593.         mktime(tuple) -> floating point number
  595.         Convert a time tuple in local time to seconds since the Epoch.
  596.         Note that mktime(gmtime(0)) will not generally return zero for most
  597.         time zones; instead the returned value will either be equal to that
  598.         of the timezone or altzone attributes on the time module.
  600.     monotonic(...)
  601.         monotonic() -> float
  603.         Monotonic clock, cannot go backward.
  605.     perf_counter(...)
  606.         perf_counter() -> float
  608.         Performance counter for benchmarking.
  610.     process_time(...)
  611.         process_time() -> float
  613.         Process time for profiling: sum of the kernel and user-space CPU time.
  615.     sleep(...)
  616.         sleep(seconds)
  618.         Delay execution for a given number of seconds.  The argument may be
  619.         a floating point number for subsecond precision.
  621.     strftime(...)
  622.         strftime(format[, tuple]) -> string
  624.         Convert a time tuple to a string according to a format specification.
  625.         See the library reference manual for formatting codes. When the time tuple
  626.         is not present, current time as returned by localtime() is used.
  628.         Commonly used format codes:
  630.         %Y  Year with century as a decimal number.
  631.         %m  Month as a decimal number [01,12].
  632.         %d  Day of the month as a decimal number [01,31].
  633.         %H  Hour (24-hour clock) as a decimal number [00,23].
  634.         %M  Minute as a decimal number [00,59].
  635.         %S  Second as a decimal number [00,61].
  636.         %z  Time zone offset from UTC.
  637.         %a  Locale's abbreviated weekday name.
  638.         %A  Locale's full weekday name.
  639.         %b  Locale's abbreviated month name.
  640.         %B  Locale's full month name.
  641.         %c  Locale's appropriate date and time representation.
  642.         %I  Hour (12-hour clock) as a decimal number [01,12].
  643.         %p  Locale's equivalent of either AM or PM.
  645.         Other codes may be available on your platform.  See documentation for
  646.         the C library strftime function.
  648.     strptime(...)
  649.         strptime(string, format) -> struct_time
  651.         Parse a string to a time tuple according to a format specification.
  652.         See the library reference manual for formatting codes (same as
  653.         strftime()).
  655.         Commonly used format codes:
  657.         %Y  Year with century as a decimal number.
  658.         %m  Month as a decimal number [01,12].
  659.         %d  Day of the month as a decimal number [01,31].
  660.         %H  Hour (24-hour clock) as a decimal number [00,23].
  661.         %M  Minute as a decimal number [00,59].
  662.         %S  Second as a decimal number [00,61].
  663.         %z  Time zone offset from UTC.
  664.         %a  Locale's abbreviated weekday name.
  665.         %A  Locale's full weekday name.
  666.         %b  Locale's abbreviated month name.
  667.         %B  Locale's full month name.
  668.         %c  Locale's appropriate date and time representation.
  669.         %I  Hour (12-hour clock) as a decimal number [01,12].
  670.         %p  Locale's equivalent of either AM or PM.
  672.         Other codes may be available on your platform.  See documentation for
  673.         the C library strftime function.
  675.     time(...)
  676.         time() -> floating point number
  678.         Return the current time in seconds since the Epoch.
  679.         Fractions of a second may be present if the system clock provides them.
  681. DATA
  682.     altzone = -32400
  683.     daylight = 0
  684.     timezone = -28800
  685.     tzname = ('Öйú±ê׼ʱ¼ä', 'ÖйúÏÄÁîʱ')
  687. FILE
  688.     (built-in)

基本运算符

以下形符属于运算符:

+ - * ** / // % @
<< >> & | ^ ~
< > <= >= == !=

#分隔符

以下形符在语法中归类为分隔符:

( ) [ ] { }
, : . ; @ = ->
+= -= *= /= //= %= @=
&= |= ^= >>= <<= **=

句点也可出现于浮点数和虚数字面值中。连续三个句点有表示一个省略符的特殊含义。以上列表的后半部分为增强赋值操作符，在词法中作为分隔符，但也起到运算作用。

以下可打印 ASCII 字符作为其他形符的组成部分时具有特殊含义，或是对词法分析器有重要意义:

’ “ # \

以下可打印 ASCII 字符不在 Python 词法中使用。如果出现于字符串字面值和注释之外将无条件地引发错误:

$ ? `

来源：https://docs.python.org/zh-cn/3/reference/lexical_analysis.html#operators

基本语法

跟着文档一步步学就可以了 https://docs.python.org/zh-cn/3/tutorial/index.html

这不再赘述

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