Author: Vamei
Source: http://www.cnblogs.com/vamei
Python built (built-in) functions as running python interpreter created. In the Python program, you can always call these functions need not be defined. The most common built-in functions are:
print("Hello World!")
In Python tutorial , we have already mentioned some of the following built-in functions:
Basic data types type ()
Far as to look at the dir () help () len ( )
Dictionary len ()
Input and output text file open ()
Cycle design range () enumerate () zip ( )
Cyclic object ITER ()
Function object map () filter () reduce ( )
Now I take are the actual parameters, you can try to effect directly on the command line.
computation
abs (-5) # absolute value, i.e. 5
round (2.6) # rounded to the nearest integer, i.e. 3.0
pow (2, 3) # 2 ** 3 corresponds, if POW (2, 3, 5), corresponding to 3% 5 2 **
cmp size (2.3, 3.2) # compare two numbers
divmod (9,2) # returns the result of the division and the remainder
max ([1,5,2,9]) # selecting the maximum value
min ([9,2, -4,2]) # for the minimum
sum ([2, -1,9,12]) # summation
Type Conversion
int ( "5") # convert integer to integer
float (2) # is converted to float float
long ( "23") # long integer into a long integer
str (2.3) # string into a string
complex (3, 9) # 3 + 9i returns the complex
ord ( "A") # "A" corresponding to the character value
chr (65) # 65 corresponding to a character value
(65) # 65 unichr value corresponding unicode character
bool (0) # is converted to the corresponding truth value in Python, corresponding to 0 False
In Python, the following objects are equivalent False: [], (), {}, 0, None, 0.0, ''
bin (56) # Returns a string that represents a binary number of 56
hex (56) # Returns a string that represents a hexadecimal number of 56
oct (56) # returns a string representing the octal number 56
list ((1,2,3)) # conversion table list
tuple ([2,3,4]) # conversion table is a fixed value tuple
slice (5,2, -1) # constructing the target object slice
dict (a = 1, b = "hello", c = [1,2,3]) # Construction dictionary Dictionary
Sequence Action
all ([True, 1, "hello!"]) # if all the elements are equivalent to the value True
any ([ "", 0, False, [], None]) # whether any element equivalent to a value of True
sorted ([1,5,3]) # Returns the positive sequence of the sequence, i.e. [3,5]
reversed ([1,5,3]) # return sequence in reverse order, that is, [3,5,1]
Classes, objects, properties
# define class
class Me(object): def test(self): print "Hello!"
def new_test():
print "New Hello!"
me = Me()
Whether hasattr (me, "test") # check me test object has properties
getattr (me, "test") # returns the test property
setattr (me, "test", new_test) # property to the test new_test
delattr (me, "test") # delete test property
isinstance (me, Me) # me Me object class object is generated (an instance)
issubclass (Me, object) # Me class is a subclass of object classes
Compile, execute
repr (me) # Returns the string representation of the object
compile ( "print ( 'Hello')", 'test.py', 'exec') # compiled code string becomes the object
eval ( "1 + 1") # explained string expression. Parameter may be compile () code object returned
exec ( "print ( 'Hello')") # string is interpreted and executed, print ( 'Hello'). Parameter may be compile () code object returned
other
input ( "Please input:") # waiting for input
globals () # Returns the global namespace, such as a global variable name, the name of a global function
locals () # Returns the local namespace