1. Python’s support for Chinese characters

#!/usr/bin/python
#coding: UTF-8
print "Hello, world";

2. Python identifier

In python, identifiers are composed of letters, numbers, and underscores.

In python, all identifiers can include English, numbers, and underscores (_), but cannot start with numbers.

#Identifiers in Python are case-sensitive.

#Identifiers starting with an underscore have special meaning. Class attributes starting with a single underscore (_foo) represent class attributes that cannot be accessed directly. They need to be accessed through the interface provided by the class and cannot be imported using "from xxx import *";

(__foo) starting with a double underscore represents the private members of the class; (__foo__) starting and ending with a double underscore represents a special identifier for special methods in python, such as __init__() representing the constructor of the class.

3. python reserved keywords

4. Python string representation

Python accepts single quotes (' ), double quotes (" ), Triple quotes (''' """) are used to represent strings. The beginning and end of the quotes must be of the same type.

Three quotation marks can be composed of multiple lines, which is a shortcut syntax for writing multi-line text. Commonly used document strings are used as comments at specific locations in the file.

word = 'word'sentence = "这是一个句子。"paragraph = """这是一个段落。
包含了多个语句"""

5. The main annotations in Python are

# or ''' ''' or "" """

6. Python data types:

• ##Numbers (number

  )

• ｛

• ｝

• int (signed integer type)

• long (long integer type [can also represent octal and hexadecimal])

• float (floating point)

• complex (plural)

• String (string) {

##The plus sign (+) is the string concatenation operator, and the asterisk (*) is the repeat operation:

• 
  !/usr/bin/python

  # -*- coding: UTF-8 -*-

  
  str = 'Hello World!'
  
  print str # Output complete characters String
  print str[0] # Output the first character in the string
  print str[2:5] # Output the third to fifth characters in the string
  print str[2:] # Output the string starting from the third character
  print str * 2 # Output the string twice
  print str + "TEST" # Output the connected string
  
  

}
List (list)
{

• 
  #!/usr/bin/python

  # -*- coding: UTF-8 -*-

  
  list = [ 'abcd', 786 , 2.23, 'john' , 70.2 ]
  tinylist = [123, 'john']
  
  print list # Output the complete list
  print list[0] # Output the first element of the list
  print list[1 :3] # Output the second to third elements
  print list[2:] # Output all elements from the third to the end of the list
  print tinylist * 2 # Output the list twice
  print list + tinylist #Print the combined list
  
  

  Output result of the above example:

  
  

  
  

  ['abcd', 786, 2.23, 'john', 70.2]
  abcd
  [786, 2.23]
  [2.23, 'john', 70.2]
  [123, 'john', 123, 'john']
  ['abcd', 786, 2.23, ' john', 70.2, 123, 'john']

• }

• Tuple

• {

• Tuples are marked with "()". Internal elements are separated by commas. But is that the tuple cannot be assigned twice, which is equivalent to a read-only list.

  
  

  #!/usr/bin/python
  # -*- coding: UTF-8 -*-
  
  tuple = ( 'abcd', 786 , 2.23, 'john', 70.2 )
  tinytuple = (123, 'john')
  
  print tuple # Output the complete tuple
  print tuple[0] # Output the tuple The first element of the group
  print tuple[1:3] # Output the second to third elements
  print tuple[2:] # Output all elements starting from the third to the end of the list
  print tinytuple * 2 # Output the tuple twice
  print tuple + tinytuple # Print the combined tuple
  

  Output result of the above example:

  
  

  ('abcd', 786, 2.23, 'john', 70.2)
  abcd
  (786, 2.23)
  (2.23, 'john', 70.2)
  (123, ' john', 123, 'john')
  ('abcd', 786, 2.23, 'john', 70.2, 123, 'john')
  

  The following tuple is invalid because Tuples are not allowed to be updated. The list is allowed to be updated:

  
  

  !/usr/bin/python
  # -*- coding: UTF-8 -*-
  
  tuple = ( 'abcd', 786 , 2.23, 'john', 70.2 )
  list = [ 'abcd', 786 , 2.23, 'john', 70.2 ]
  tuple[2] = 1000 # Tuple Illegal applications are in
  list[2] = 1000 # Legal applications are in the list

• ##}

• Dictionary

• {

• Dictionaries are identified with "{ }". A dictionary consists of an index (key) and its corresponding value.

  
  

  #!/usr/bin/python
  # -*- coding: UTF-8 -*-
  
  dict = {}
  dict['one'] = "This is one "
  dict[2] = "This is two"
  
  tinydict = {'name': 'john','code':6734, 'dept': 'sales'}
  
  
  print dict['one'] # Output the value with key 'one'
  print dict[2] # Output the value with key 2
  print tinydict # Output the complete dictionary
  print tinydict .keys() # Output all keys
  print tinydict.values() # Output all values ​​
  

  The output result is:

  
  

  This is one This is two {'dept': 'sales', 'code': 6734, 'name': 'john'} ['dept', 'code', 'name'] ['sales', 6734, 'john ']

• ##}

7. Python data type conversion

8. Python’s operators

Python’s arithmetic operators

Python comparison operators

Python’s assignment operator

#!/usr/bin/python# -*- coding: UTF-8 -*-import time;  # 引入time模块ticks = time.time()print "当前时间戳为:", ticks

当前时间戳为: 1459994552.51

#!/usr/bin/python# -*- coding: UTF-8 -*-import time

localtime = time.localtime(time.time())print "本地时间为 :", localtime

本地时间为 : time.struct_time(tm_year=2016, tm_mon=4, tm_mday=7, tm_hour=10, tm_min=3, tm_sec=27, tm_wday=3, tm_yday=98, tm_isdst=0)

#!/usr/bin/python# -*- coding: UTF-8 -*-import time

localtime = time.asctime( time.localtime(time.time()) )print "本地时间为 :", localtime

本地时间为 : Thu Apr  7 10:05:21 2016

time.strftime(format[, t])

#!/usr/bin/python# -*- coding: UTF-8 -*-import time# 格式化成2016-03-20 11:45:39形式print time.strftime("%Y-%m-%d %H:%M:%S", time.localtime()) # 格式化成Sat Mar 28 22:24:24 2016形式print time.strftime("%a %b %d %H:%M:%S %Y", time.localtime()) 
  # 将格式字符串转换为时间戳a = "Sat Mar 28 22:24:24 2016"print time.mktime(time.strptime(a,"%a %b %d %H:%M:%S %Y"))

2016-04-07 10:25:09Thu Apr 07 10:25:09 20161459175064.0

#!/usr/bin/python# -*- coding: UTF-8 -*-import calendar

cal = calendar.month(2016, 1)print "以下输出2016年1月份的日历:"print cal;

以下输出2016年1月份的日历:
    January 2016Mo Tu We Th Fr Sa Su
             1  2  3
 4  5  6  7  8  9 1011 12 13 14 15 16 1718 19 20 21 22 23 2425 26 27 28 29 30 31