PowerPoint

Python Moon Yong Joon1

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zen of python3

zen of python

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platform5

platform module platform

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Python 2to3 http://www.diveintopython3.net/porting-code-to-python-3-with-2to3.html

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__future__10

3.X Python 2to3

print 11

/

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literal expression13

literal expression literal expression ,

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OperatorDescription**Exponentiation (raise to the power)~ + -Ccomplement, unary plus and minus (method names for the last two are +@ and -@)* / % //Multiply, divide, modulo and floor division+ -Addition and subtraction>> =Comparison operators == !=Equality operators= %= /= //= -= += *= **=Assignment operatorsis is notIdentity operatorsin not inMembership operatorsnot or andLogical operators

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Division : 18

, operator

2. int 3. __future__ division import 3. 19

special method / __truediv__ // __floordiv__

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Expression

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Expression generator

Generator expression 23

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var, obj var obj class var, obj

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( Reference Variable) , Variable ,

Variable = ()

( )27

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None Variable ,

Variable = ()

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i

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(value & Type)

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instance object class object Class objectInstanceobject

Type Value new

Value/Type34

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(Variable) (object) ,

Variable ,

Variable = ()36

Type 37

Type inference l . .

.

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new

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Int Float int isdigit() True

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float int float

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//

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: , ,,,

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( ) Private (property, ) Private( ) , (special method) 48

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namespace

namespaceoperator

operator 50

Special 51

Special __special__

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Keywords

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Keyword54

Keyword keyword keyword import (2.7)

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Keyword : 2.x 2.7 Keywordandelififprintaselseimportraiseassertexceptinreturnbreakexecistryclassfinallylambdawhilecontinuefornotwithdeffromoryielddelglobalpass

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Keyword : print(2.x) 2.x 3. __future__ import print

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Keyword : 3.x 3.x Keywordandelifimportraiseaselseinreturnassertexceptistrybreakfinallylambdawhileclassfor nonlocalwithcontinuefromnotyielddefglobalordelifpass

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print59

Print : 2.7 print

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=

iii + 1 Unbinding (NameError: name 'iii' is not defined)63

binding() Scope I + 1 I I NameError: name 'i' is not defined ( ) .

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namespace , class, instance global globals() locals()class __dict__instance __dict__66

class method : class class namespace class. GlobalCount = 100Class AA.Count = 1

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Reference Variable () reference binding

dir() context 69

namespace: dict type global . Globals context

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namespace: globals [], = global

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binding 72

Variable

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Variable Context .del , del()

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Chained Assignments78

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Augmented Assignments80

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operator

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Operator 83

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OperatorDescriptionExample+AdditionAdds values on either side of the operator.a + b = 30- SubtractionSubtracts right hand operand from left hand operand.a b = -10* MultiplicationMultiplies values on either side of the operatora * b = 200/ DivisionDivides left hand operand by right hand operandb / a = 2% ModulusDivides left hand operand by right hand operand and returns remainderb % a = 0** ExponentPerforms exponential (power) calculation on operatorsa**b =10 to the power 20//Floor Division - The division of operands where the result is the quotient in which the digits after the decimal point are removed.9//2 = 4 and 9.0//2.0 = 4.0

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OperatorDescriptionExample=Assigns values from right side operands to left side operandc = a + b assigns value of a + b into c+= Add ANDIt adds right operand to the left operand and assign the result to left operandc += a is equivalent to c = c + a-= Subtract ANDIt subtracts right operand from the left operand and assign the result to left operandc -= a is equivalent to c = c - a*= Multiply ANDIt multiplies right operand with the left operand and assign the result to left operandc *= a is equivalent to c = c * a/= Divide ANDIt divides left operand with the right operand and assign the result to left operandc /= a is equivalent to c = c / ac /= a is equivalent to c = c / a%= Modulus ANDIt takes modulus using two operands and assign the result to left operandc %= a is equivalent to c = c % a**= Exponent ANDPerforms exponential (power) calculation on operators and assign value to the left operandc **= a is equivalent to c = c ** a//= Floor DivisionIt performs floor division on operators and assign value to the left operandc //= a is equivalent to c = c // a

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: and, or, xorOperatorDescription& Binary AND | Binary OR ^ Binary XOR

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: ~, OperatorDescription~ Binary Ones Complement1 > Binary Right Shift .

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OperatorDescriptionExampleand Logical ANDIf both the operands are true then condition becomes true.(a and b) is true.or Logical ORIf any of the two operands are non-zero then condition becomes true.(a or b) is true.not Logical NOTUsed to reverse the logical state of its operand.Not(a and b) is false.

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: and/or

and : true and : false

or : true or : false 93

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OperatorDescriptionExample==If the values of two operands are equal, then the condition becomes true.(a == b) is not true.!=If values of two operands are not equal, then condition becomes true.If values of two operands are not equal, then condition becomes true.(a b) is true. This is similar to != operator.>If the value of left operand is greater than the value of right operand, then condition becomes true.(a > b) is not true.=If the value of left operand is greater than or equal to the value of right operand, then condition becomes true.(a >= b) is not true.