A variable declaration and assignment:
Variable declaration and assignment for telling a variable bound to an object
Format is as follows:
1. variable name = expression
Second, delete variables and garbage collection:
You can delete by the del statement variable is not used, if the object is not variable references, it will be recovered garbage collector, clear memory space.
a = 123
of the
Third, the chain assignment:
Assignment chain for the same object multiple variables assignment
x = y = 123 is equivalent to: x = 123; y = 123
Series unpacking assignment :( number must be consistent)
a, b, c = 4,5,6 corresponds to a = 4; b = 5; c = 6
Example: a, b = 1,2
a,b = b,a
Fourth, the constant
python does not support constant, that is, no grammar rules limit change a constant value. We can only naming convention constants,
And not in the constant logic value to make changes.
MAX_SPEED = 120
print(MAX_SPEED)
Fifth, each object has a type, python most basic built-in data types:
1. Plastic: 123 2. Float: 3.14 3. decimal Boolean: true and false indicates, contains only True, False 4. string types: the sequence of characters. "Abc"; "Beijing";