Python 1 day

Python Basics-Basics

1. The first python-suffix name can be arbitrary?
-When importing a module, if it is not a. py file
==> after the file suffix name is. py

2. Two modes of execution
Python interpreter py file path
Python enters the interpreter:
Real-time input and get to execution results

3. Interpreter Path
#!/usr/bin/env python

4. Encoding
#-*-Coding:utf8-*-

Ascill 00000000 (8-bit)

Unicode 0000000000000000+ (16-bit)

How many utf-8 can be expressed by how many means

Note:

Python3 no concern
Python2 each file appears in Chinese, the head must be added

Bytes, bits
Unicode UTF8 GBK
Utf8:3 (a Chinese occupies a few bits)
Gbk:2

5. Perform an action
Reminder user input: User and password
Get user name and password, detect: Username =root password =root
Correct: Login Successful
Error: Login failed

6. Variable Name

-Alphabet
-Digital
-Underline
Note:
Number cannot start
cannot be a keyword
It's best not to repeat the python built-in stuff.

7. Conditional statement (indent with 4 spaces)

A.

#!/usr/bin/env python
N1 = input ('>>>')                    if "Alex"=="Alex": N2= Input ('>>>')    ifN2 = ="Confirm":        Print('Alex SB')    Else:        Print('Alex DB')Else:    Print('Error') Note: N1="Alex"Assignment N1=='Alex'Comparison

Description

if condition 1:     Pass elif Condition 2:     Pass elif Condition 3:     Pass Else :     Pass    Print ('end')

C. Conditions

 and  or        ifN1 = ="Alex" orN2 = ="alex!23":        Print('OK')    Else:        Print('OK') PS:Passsubstituting null code, meaningless, just to represent a block of codeContinue: Terminates the current loop, starting the next loop Break: Terminates the usage of all loop input, waits forever until the user enters a value, assigns the input value to a thing

8. Cycle

dead Loop  while 1==1:    print('ok')

9. Basic data types

String: N1 ="Alex"N2 ='Root'N3 ="""Eric"""n4=" "Tony" "Number:age=21 weight = Fight = 5subtraction, etc.: string: addition: N1="Alex"N2="SB"N4="DB"N3= n1 + N2 +N4#"Alexsbdb"Multiplication: N1="Alex"N3= N1 * 10numbers: N1= 9N2= 2N3= n1 +n2 N3= N1-n2 N3= N1 *n2 N3= N1/n2 N3= N1%n2 N3= N1 * *N2
Exercise: Determine whether a number is an even or a number of KikiNum= 12N= num% 2ifn = =0:Print('even')    Else:        Print('Odd')

Exercises:
If condition statement
While loop
Odd even

1. Use while loop input 1 2 3 4 5 6. 8 9 10

# !/usr/bin/env pythonn = 1 while n < one:    if n = =7        :Pass    Else:        print(n)    = n + 1print(' ----End---- ')

2. For all numbers of 1-100

#!/bin/usr/env python
n = 1= 0 while n < 101:    = s + n                            = n + 1print(s)

3. All odd numbers in output 1-100

#!/usr/bin/evn python
n = 1 while n < 101:    = n 2    if temp = = 0:        pass    else
    :        print(n)    = n + 1print('----END----  ')

4. All even numbers in output 1-100

#!/usr/bin/env python
n = 1 while n < 101:    = n 2    if temp = = 0:        print(n)    
    Else:        pass    = n + 1print('---- End----')

5, Beg 1-2+3-4+5 ... 99 of all numbers of the and

n = 1#  S is the sum of all previous numbers  while n <:    = n% 2    if temp = = 0:         = S- n        else:        = s + n                            = n + 1print(s)

6. User Login (three chance retry)

#!/bin/usr/env python
Count =0 whileCount < 3User= Input ('>>>') PWD= Input ('>>>')    ifuser_id = ="Root"   andUser_pass = ="Root":        Print "is OK"         Break    Else:        Print('user or pass is error') Count= Count + 1

Python 1 day