Coding:
ASCII code: The standard ASCII code is encoded using a 7-bit binary code, and when the ASCII code is represented by 1 bytes (8-bit binary code), 1 0 is added at the highest bit.
An English letter takes up one byte
8-bit (bit) = = one byte (byte)
1024byte=1kb
1024kb==1mb
1024mb=1gb
1024gb==1tb
Unicode: in order to solve the problem of the globalization of ASCII, there was a unicode,unicode stipulation that a Chinese is expressed in 4 bytes, and an English is expressed in 1 bytes.
Utf-8: In fact, the upgrade version of Unicode, the provision of English with 1 bytes, Chinese characters are represented by 3 bytes.
Logical operators:
Logical operators have not,or, and.
The operation precedence of these operators is: () >not>and>or
Equal priority left-to-right start operation
For example:
and or and or 9 < 8)print(a)
Results:
False
conversion between INT and bool:
a=Int (True) B=int (False)print(A, B)
Results:
12
Rint (BOOL (1))print(bool (3))print(bool (0))
Results:
Truetruefalse
Interview questions:
1. Print (x or y), if X is true, the result is x. Otherwise the result is Y.
Examples:
Print or 5)printor 8)print( -1or 0)
The result is:
38-1
2. Print (x and y), if X is true, the result is Y, and if Y is false, the result is X.
Example:
Print and 5)print and 8)print and 0)
The result is:
5xx
Example:
Print or or and or 2)
The result is:
3
The use of in and not:
Example
Sl="abcdefg"print("a" in SL) Print ("ad"in#"ad" is equivalent to an element as a whole, instead of "a" "B" being disassembled like this.)
Results:
TrueFalse
Title: The content of the commentary can not have sensitive words such as "Xi Big", "Kuomintang", "Chiang Kai-shek"
Answer:
Comment=input ("Please enter a comment")if("XI greatly"inchComment)or("KMT" inchComment)or("Chiang Kai"inchcomment):Print("the comments contain sensitive words")Else: Print("Comment Success")
Note: The key to this problem is that the sensitive word should be in comments instead of commet in sensitive words.
Python basic 2 encoding and logical operators