Python Study (3) - Numeric Type

We will talk about in-depth of python data type. Numeric type is basic types of Python language.

Data Type Classic
We can classify these type to follow as =>

  (1) Integer and floating-point objects : 1234, 1.23, 14e-10
       sign : e or E  is exponent. Python 3.x only has integer (normal and long have
       been merged) but Python 2.x , it still are  two integer types and normal.
  (2) Complex number objects : 3+4j, j
  (3) Decimal Obejct : Decimal(‘2.1456’)
  (4) Fraction : Fraction(-8,5)
  (5) Sets  : set(“apple”)
  (6) Boolean Object :Ture or False, Bool , 1
  (7) Numeric module(build-in libraries) : random, math
  (8) Third-party extension : vector, plotting


Operation function

Operator	Example
express operators	+, -, *, /, >>, **, &, >>> 1+1 2
Built-in mathematical functions	pow, abs, round ….
module	random, math,

Expression operators

Operators	Description
or	Logical OR => x or y
and	Logical AND => x and y
x<y, x<=y, x>y, x>=y
x==y, x!=y	Logical equal , not equal
x | y	Bitwise OR
x ^ y	Bitwise XOR
x <<y , x >>y	Shift x left or right by y bits
+, -, *, /, %
//	floor
~x	Bitwise Not
x[i], x[i:j]	retrive sub slicing
[]	list
{}	dictionary
()	tuple
x in y, y not in x	membership
foor

Integer and float
In Python 2.0, Integer is represented by “L” , but it is none in python 3.0.

*Python 2.0
>>>3 ** 200
265613988875874769338781322035779626829233452653394495974574961739092490901302182994384699044001L

*Python 3.0
>>>3 ** 200
265613988875874769338781322035779626829233452653394495974574961739092490901302182994384699044001

Complex Numbers
Complex Numbers divide into real number and imaginary,  J or j suffix to the imaginary part.

>>> (1+1j) * 1j (-1+1j)   >>> 1+1j*3 (1+3j) >>> j * j -1

          
Fraction Type
   (1) 1/2 is represented to Fraction( 1 , 2 )
   (2) accurate , Ex: 0.1 + 0.1 + 0.1 -0.3 and Fraction(1, 10) + Fraction(1, 10)  + Fraction(1, 10)
                                - Fraction(3, 10)
   

>>> from fractions import Fraction >>> Fraction(1,10) + Fraction(1,10) Fraction(1, 5) >>> Fraction(2,5) - Fraction(1,5) Fraction(1, 5) >>> Fraction(2,5) * Fraction(1,5) Fraction(2, 25) >>> Fraction("0.25") Fraction(1, 4) >>> Fraction("0.3") + Fraction("0.1") Fraction(2, 5) >>> 0.1 + 0.1 + 0.1 -0.3  # The result should be 0 5.551115123125783e-17 >>> Fraction(1, 10) + Fraction(1, 10) + Fraction(1, 10) - Fraction(3, 10) Fraction(0, 1) >>>from decimal import Decimal >>> Decimal('0.1') + Decimal('0.1') + Decimal('0.1') - Decimal('0.3') Decimal('0.0') >>> 1/3 0.3333333333333333

          
Sets
(1) It is  not unordered and non-duplicated a of collection items.
(2) It is used to  “ {}”  to represent element of the sets 

>>> food = {'apples', 'banana'} >>> food set(['banana', 'apples']) >>> type(food) <type 'set'>

set  operator
x = set("apple") ,  y = set("banana")

Operators	Description	Example
-	different	>>> x – y set(['p', 'e', 'l'])
| or Union	Union	>>> x | y set(['a', 'p', 'b', 'e', 'l', 'n']) >>> x.union(y) set(['a', 'p', 'b', 'e', 'l', 'n'])
&	Intersection	>>> x &  y set(['a'])
^	Symmetric different(XOR)	>>> x ^ y set(['b', 'e', 'l', 'n', 'p'])
< , >	superset, subset	>>> x > set(“a”) True >>> x > set(“b”) Flase
in	include	>>> “a” in x True
add(Object)	insert into one to the set	>>> x.add("apple") >>> x set(['a', 'p', 'e', 'l', 'apple'])
update(Obejct)	update set  the set	>>> x.update("a","b") >>> x set(['a', 'p', 'b', 'e', 'l'])
remove(Objcet)	remove	>>> x.remove('a') >>> x set(['p', 'e', 'l'])

Note : {} is still a dictionary in all Python.

>>> type({})   # don’t {} and space element <class 'dict'> >>> s = set() >>> type(s) <class, ‘set’>

Advanced  

>>> { x*4  for x in 'apple'} set(['aaaa', 'llll', 'pppp', 'eeee'])

Boolean
  
  (1)  Boolean  is the same as 1 , Ex:  True = 1

>>> type(Ture) <class, ‘bool’>