1, Pycharm installation and use
Community Edition
Professional English Version
2. Formatted output: %s %d%f
3，While 。。。Else
When the while loop is interrupted by break , the else program is not executed
4. Operator
Logical operators and and (zero with zero) or or (or one with one) not not
In the first case, logical operators are preceded and followed by comparison operations
Priority: () > not > and > or , same level from left to right
In the second case, the logical operator is preceded by numbers
x or y , if x is true, the value is x , if x is false, the value is y ;
x and y, x is true, value is y, x is false, value is x .
bool value conversion
Int----->bool non-zero is True , zero is False
Bool----> int True is 1 , false is 0 .
numbers with
5. First knowledge of coding
The storage of computer files and the transmission of files are both 0101
Primary password book ascii letters special characters and numbers 8 bits == 1 byte
A byte represents a character
Characters: the smallest unit of content
Universal code : At the beginning of unicode creation, 16 bits and two bytes represent a character.
Upgrading 32 bits to four bytes represents a character.
waste of resources
Upgrade utf-8 to unicode : use a minimum of 8 digits to represent a character
China - China: use three bytes
European script : two bytes
Gbk : National standard. One byte for letters, two bytes for Chinese characters