1. Mathematical operations
abs(-5) # Equivalent to 2**3, if it is pow (2, 3, 5), equivalent to 2**3 % 5
cmp(2.3, 3.2) ,2,9]) # Find the maximum value
min([9,2,-4,2]) # Find the minimum value
sum([2,-1,9,12]) # Find the sum
2. Type Convert
int("5") # Convert to integer
float(2) # Convert to floating point number float
long("23") # Convert to long integer
str(2.3) # Convert to string
complex(3, 9) # Return the complex number 3 + 9i The character corresponding to 65
unichr(65) # The unicode corresponding to the value 65 Character lBool (0) # Convert to the corresponding authentic values. In Python, 0 is equivalent to false. In python, the following objects are equivalent to false: ** [], (), {}, 0, none , 0.0, '' **
bin(56) 6) # Return A string representing the octal number 56
list((1,2,3)) ,-1) , "hello!"]) # Whether all elements are equivalent to True value
any(["", 0, False, [], None]) # Whether any element is equivalent to True value
sorted([1 )Reversed ([1,5,3]) # Returns the sequence of the backflow, which is [3,5,1]
4, class, object, attributes
# define class
Class me (Object):
DEF TEST ( self): me, "test") # Return the test attribute
setattr(me, "test", new_test) # Set the test attribute to new_test
delattr(me, "test") # Delete the test attribute
isinstance(me, Me) # me Whether the object is an object generated by the Me class (an instance)
issubclass(Me, object) # Whether the Me class is a subclass of the object class
5. Compilation and execution
repr(me) # Return the string expression of the object
compile ("Print ('hello')", 'test.py', 'exec') # compile string becomes CODE object
eval ("1 + 1") # Explanation string expression. The parameter can also be the code object returned by compile()
exec("print('Hello')") # Interpret and execute the string, print('Hello'). The parameter can also be the code object returned by compile()
6, others
input("Please input:") # Return to local namespace