Python Notes---DAY1: basic operations, if statements

1. Output string:

Print (" string ")

2. Open the document file with python :

CMD Command indicator

CD C + + where cd is Chang directory Change directory, with tab key to quickly find the target file

Dir View current directory file list

3, thecmd operation:

D: The second time you change the directory without adding \

CD: return to the previous level directory

Cd.. \.. go back to the two-level directory

Execute Command Destination file directory open a file with the program you are using

Exit exits

-V View version

4. Description Data:

Student_numbers=1 using underscores instead of spaces

Studentnumbers=1 Hump Body

Pie=3.14 constants All in uppercase

5. Delete variables:

Del variable

6. View variable types:

Print (Type ( variable ))

7. Comments:

# Command line comment

"' command

command ' multiline comment '

8. Interactive applet:

death_age=100

Name=input ("Your Name:") input result defaults to string

Age=input ("Your Age:")

Print ("Can Live", death_age-int (age), "years!")

string to Integer:int ( data )

Integer to string:str ( data )

9, Guess the Age program:

age_of_god=100

Guess_age=int (Input ("Guess_age:"))

If age_of_god==guess_age: use double equals when judging

Print ("You are right!") Note tab indent

Else

Print ("You are wrong!")

10. Multi-Branch if statement:

Score=int (Input ("score:"))

If score>90:

Print ("A")

Elif Score>80:elif=else If

Print ("B")

Elif score>70:

Print ("C")

Else

Print (" dumb ")

Python Notes---DAY1: basic operations, if statements