Python origin variable and if loop

One. The origins of Python
Python is an interpreted weak-type programming language.
Features: Simple. Clear. Elegant

Two. Python's Interpreter
CPython. provided by the official. Internal use of C language to achieve
PyPy. Interpret our code as a bytecode file at once. can go directly to run.

Three. The first Python program
Print (any content)

Print (3+5+6) print ((3+5+6) *12) print (((3+5+6) *12) +3)

　　

Four. Variable
The intermediate values that are generated during the run of the program. Temporarily saved in memory. For use in later programs
Naming rules:
1. Use letters, numbers, underscores
2. Cannot start with a number, not a pure number
3. You cannot use the Python keyword
4. Not too long
5. To make sense
6. Case-sensitive
7. Do not use Chinese
8. It is recommended to use the hump or underline

A = 3+5+6     # Here's a is a variable. Temporarily records a value. For subsequent programs to continue using Execute print (a*12)     # 168

b = A       # execution order. Assigns the value to the right of the equal sign to the variable to the left of the equal sign print (b)     #168

Five. The data type of the variable
1. Int. Integer. Can do +,-, *,/,% (calculates remainder, modulo),//(divisible)

Print (10%3) print (10//3)

2. Str. String. can be + * ', ', ' ', ' "", "the lavish content called string

Alex = "" "Black Eat" "" type () to see the data type of the variable alex = 18print (Alex) s = "The girl across the street looked over and looked over." It's hard to resist. Arrangement ' Print (s)

3. bool. Boolean value. 　　A value of two. True, False can only be used to determine the condition

Six. User interaction
variable = input (Prompt)

variable = input ("prompt") content = input ("Did you eat?") Print ("We received at the console:" +content) lets the user enter a, allowing the user to enter B. The computer calculates the result of a+b a = input ("Please enter A:") # input received is STRB = input ("Please enter B:") # input received is STR

The received content is a string type
str = > int + = int (str)

#将字符串转换成整数  Int (string) c = Int (a) + int (b) print (c)

Seven. Process Control (IF)

    If condition:        code block    If condition 1:        code block 1    Else:        code block 2    if condition 1:        code block    elif Condition 2:        code block elif ...    . else: If condition: If condition:                code block        else:    else:

　

Content = input ("Please enter if you have won:") if content = = ' is ': # = assignment.  = = Judge Print ("Go to the top    of Life")    print ("Buy it first 20 houses") Else: Print ("    live the life of the Cock")    print ("I'm going to die")

　　

Print ("Crashed crashed crashed, who?") gender = input ("Excuse me, are you a man or a woman?") if gender = = ' man ':    Pass #  Pass. Indicates the integrity of the grammar    print ("The man went next door." Find Alex. ") else:   # is not a man's age    = input ("Dalglish this year?")    if int >: # input receives a string. 48 is int. These two data types are not comparable to        print ("Auntie, who are you looking for?")    Else:        print ("My melon, especially sweet.")

　　

　

Python origin variable and if loop