Data types and variables
1: integer; float; string (string, "to represent; there are some escape character);
2: integer and floating-point numbers can be infinite; there is no limit of the number of bits;
3: Boolean values are true and false; Null none; at pl / sql as is null;
4: Python variable type is not fixed is called dynamic languages;
5: / (float result); // (the result is an integer)% (result is the remainder)
Strings and coding
ASCII-> UNICODE-> UTF-8
English - "Multi-language -" to save the letters footprint;
For encoding a single character, Python provides the ord () function to get the character integer, chr (transcoding function to the corresponding character);
Python data bytes belt type single quotes or double quotes b prefix indicates (on the network and stored on the hard disk is represented by bytes);
To calculate str contains how many characters you can use len () function;
len () function calculates the number of characters of str, if changed bytes, len () function computes the number of bytes;
In Python, using C language and formatting manner consistent, implemented%;
% Operator is used to format string. Within the string, the string is represented by S% Alternatively,% d represents an integer Alternatively, a few%? Placeholder, just behind several variables or a value, the order to the corresponding well. If only one percent ?, parenthesis may be omitted;
format ()
Another method is to use a string formatted string format () method, which in turn replaces the placeholder in the passed string argument;
