자료형과 연산자

# int

year = 2014

month = 10

print("year, month:", year, month)

# 8, 16, 2 진수 표현  

print("0o10, 0x10, 0b10:", 0o10, 0x10, 0b10)

# 10진수를 8, 16, 2진수로 변환 

print("oct(10):", oct(10))

print("hex(10):", hex(10))

print("bin(10):", bin(10))

# 정수형 표현 int

print("type(2**31):", type(2**31))

# 실수형 표현 float

print("type(3.14):", type(3.14))

print("type(314e-2):", type(314e-2))

# 복소수, 켤레복소수

x = 3 - 4j

print("type(x):", type(x))

# 원의 넓이 

r=2

circle_area = 3.14*(r**2)

print("circle_area:", circle_area)

# 삼각형의 넓이 

x=3

y=4

triangle_area = x*y/2

print("triangle_area:", triangle_area)

# 나누기, 정수 나누기 

print("3/2:", 3/2)

print("3//2:", 3//2)

# 문자열 

print(type("sting"))

print(type('string'))

print(type("""string"""))

print(type('''string'''))

print("""

테스트 스트링

줄바꿈도 저장되고

탭도    저장되고

""")

print("\t탭\n다음줄")

print(r"r은 raw문자열 \t탭\n다음줄")

print('hello.' 'eunmi')

print('hello.'+'eunmi')

print('hi!'*3)

# 인덱싱, 배열처럼 0부터 시작, 치환은 안됨 

a="python"

print("a:", a)

print("a[0]:", a[0])

print("a[5]:", a[5])

# error

# a[0] = "a"

# TypeError: 'str' object does not support item assignment

# a[0] = "a"

# print(a[0])

# 슬라이싱 

print("a[0:1]=", a[0:1])

print("a[1:4]=", a[1:4])

print("a[:2]=", a[:2])

print("a[-2:]=", a[-2:])

print("a[:]=", a[:])

print("a[::2]=", a[::2])

# 생성자 

print("str(3.14)=", str(3.14))

print("int(3)=", int(3))

print("float(3.14)=", float(3.14))

# 유니코드 (기본적으로 모두 유니코드, 인코딩이 있는 문자는 byte로 표현 

print("type('가'):", type('가'))

print("'가'.encode('utf_8'):", '가'.encode('utf_8'))

print("type('가'.encode('utf_8')):", type('가'.encode('utf_8')))

print("ord('s'):", ord('s'))

print("chr(115):", chr(115))

# 리스트, 순서 있음  

colors = ['red', 'green', 'blue']

print("colors:", colors)

print("type(colors):", type(colors))

colors.append('gold')

print("colors:", colors)

colors.insert(1, 'yellow')

print("colors:", colors)

colors.extend(['white', 'black', 'gray'])

print("colors:", colors)

colors += ['red']

print("colors:", colors)

colors += 'red'

print("colors:", colors)

print("colors.index('red'):", colors.index('red'))

print("colors.index('red', 1):", colors.index('red', 1))

# print(colors.index('red', 1, 5))

# Traceback (most recent call last):

#  File "/Users/eunguru/Source/Python/Type_Operator/src/Type_Operator.py", line 108, in <module>

#    print(colors.index('red', 1, 5))

# ValueError: 'red' is not in list

print("colors.count('red'):", colors.count('red'))

colors.pop()

colors.pop()

colors.pop()

print("colors:", colors)

colors.pop(1)

print("colors:", colors)

colors.remove('red')

print("colors:", colors)

colors.sort()

print("colors:", colors)

colors.reverse()

print("colors:", colors)

def mysort(x): return x[-1]

colors.sort(key=mysort)

print("colors:", colors)

colors.sort(key=mysort, reverse=True)

print("colors:", colors)

# 세트, 순서 없음 

a = {1, 2, 3}

b = {3, 4, 5}

print("a:", a)

print("b:", b)

print("type(a):", type(a))

print("a.union(b):", a.union(b))

print("a|b:", a|b)

print("a.intersection(b):", a.intersection(b))

print("a&b:", a&b)

print("a-b:", a-b)

# 튜플, 읽기 전용 

t = (1, 2, 3)

print("t:", t)

print("type(t):", type(t))

print("t.count(1):", t.count(1))

print("t.index(2):", t.index(2))

a, b = 1, 2

print("a, b:", a, b)

(a, b) = (1, 2)

print("a, b:", a, b)

a, b = b, a

print("a, b:", a, b)

# list(), set(), tuple()

a = (1, 2, 3)

print("a:", a, "type(a):", type(a))

b = list(a)

print("b:", b, "type(b):", type(b))

c = set(b)

print("c:", c, "type(c):", type(c))

d = tuple(c)

print("d:", d, "type(d):", type(d))

# in 연산자 

print("1 in a:", (1 in a))

print("2 in b:", (2 in b))

print("3 in c:", (3 in c))

print("4 in c:", (4 in c))

# 사전(dictionary), key:value pair

d = dict(a=1, b=3, c=5)

print("d:", d)

print("type(d):", type(d))

color = {"apple":"red", "banana":"yellow"}

print("color:", color)

print("color[\"apple\"]:", color["apple"])

# print("color[0]:", color[0])

#Traceback (most recent call last):

#File "/Users/eunguru/Source/Python/Type_Operator/src/Type_Operator.py", line 179, in <module>

#print("color[0]:", color[0])

#KeyError: 0

color["cherry"] = "red"

print("color:", color)

color["apple"] = "green"

print("color:", color)

for c in color.items():

    print(c)

for k, v in color.items():

    print(k, v)

for k in color.keys():

    print(k)

for v in color.values():

    print(v)

print("type(color.keys()):", type(color.keys()))

print("type(color.values()):", type(color.values()))

print("type(color.items()):", type(color.items()))

print(color)

print("list(color.keys()):", list(color.keys()))

del color["cherry"]

print("color:", color)

color.clear()

print("color:", color)

s = {'age':40.5, 'job':[1,2,3], 'name':{'kim':2, 'Cho':1}, 'num':(3,4,5), 'set':{1,2,3}}

print("s:", s)

print("type(s):", type(s))

# 부울 

isRight = False

print("isRight:", isRight, "type(isRight):", type(isRight))

print("1 < 2:", 1<2)

print("1 != 2:", 1!=2)

print("1 is not 2:", 1 is not 2)

print("1 == 2:", 1==2)

print("1 is 2:", 1 is 2)

print("True and True:", True and True)

print("True & True:", True & True)

print("True & False:", True & False)

print("True or False:", True or False)

print("True | False:", True | False)

print("not False:", not False)

print("bool(0):", bool(0))

print("bool(-1):", bool(-1))

print("bool('test'):", bool('test'))

print("bool(None):", bool(None))

# 얕은 복사 

a = [1,2,3]

b = a

a[0] = 38

print("a:", a, "b:", b)

print("id(a):", id(a), "id(b):", id(b))

# 깊은 복사  

c = [1,2,3]

d = c[:]

print("c:", c, "d:", d)

print("id(c):", id(c), "id(d):", id(d))

c[0] = 38

print("c:", c, "d:", d)

year, month: 2014 10

0o10, 0x10, 0b10: 8 16 2

oct(10): 0o12

hex(10): 0xa

bin(10): 0b1010

type(2**31): <class 'int'>

type(3.14): <class 'float'>

type(314e-2): <class 'float'>

type(x): <class 'complex'>

circle_area: 12.56

triangle_area: 6.0

3/2: 1.5

3//2: 1

<class 'str'>

<class 'str'>

<class 'str'>

<class 'str'>

테스트 스트링

줄바꿈도 저장되고

탭도    저장되고

탭

다음줄

r은 raw문자열 \t탭\n다음줄

hello.eunmi

hello.eunmi

hi!hi!hi!

a: python

a[0]: p

a[5]: n

a[0:1]= p

a[1:4]= yth

a[:2]= py

a[-2:]= on

a[:]= python

a[::2]= pto

str(3.14)= 3.14

int(3)= 3

float(3.14)= 3.14

type('가'): <class 'str'>

'가'.encode('utf_8'): b'\xea\xb0\x80'

type('가'.encode('utf_8')): <class 'bytes'>

ord('s'): 115

chr(115): s

colors: ['red', 'green', 'blue']

type(colors): <class 'list'>

colors: ['red', 'green', 'blue', 'gold']

colors: ['red', 'yellow', 'green', 'blue', 'gold']

colors: ['red', 'yellow', 'green', 'blue', 'gold', 'white', 'black', 'gray']

colors: ['red', 'yellow', 'green', 'blue', 'gold', 'white', 'black', 'gray', 'red']

colors: ['red', 'yellow', 'green', 'blue', 'gold', 'white', 'black', 'gray', 'red', 'r', 'e', 'd']

colors.index('red'): 0

colors.index('red', 1): 8

colors.count('red'): 2

colors: ['red', 'yellow', 'green', 'blue', 'gold', 'white', 'black', 'gray', 'red']

colors: ['red', 'green', 'blue', 'gold', 'white', 'black', 'gray', 'red']

colors: ['green', 'blue', 'gold', 'white', 'black', 'gray', 'red']

colors: ['black', 'blue', 'gold', 'gray', 'green', 'red', 'white']

colors: ['white', 'red', 'green', 'gray', 'gold', 'blue', 'black']

colors: ['red', 'gold', 'white', 'blue', 'black', 'green', 'gray']

colors: ['gray', 'green', 'black', 'white', 'blue', 'red', 'gold']

a: {1, 2, 3}

b: {3, 4, 5}

type(a): <class 'set'>

a.union(b): {1, 2, 3, 4, 5}

a|b: {1, 2, 3, 4, 5}

a.intersection(b): {3}

a&b: {3}

a-b: {1, 2}

t: (1, 2, 3)

type(t): <class 'tuple'>

t.count(1): 1

t.index(2): 1

a, b: 1 2

a, b: 1 2

a, b: 2 1

a: (1, 2, 3) type(a): <class 'tuple'>

b: [1, 2, 3] type(b): <class 'list'>

c: {1, 2, 3} type(c): <class 'set'>

d: (1, 2, 3) type(d): <class 'tuple'>

1 in a: True

2 in b: True

3 in c: True

4 in c: False

d: {'c': 5, 'a': 1, 'b': 3}

type(d): <class 'dict'>

color: {'apple': 'red', 'banana': 'yellow'}

color["apple"]: red

color: {'apple': 'red', 'cherry': 'red', 'banana': 'yellow'}

color: {'apple': 'green', 'cherry': 'red', 'banana': 'yellow'}

('apple', 'green')

('cherry', 'red')

('banana', 'yellow')

apple green

cherry red

banana yellow

apple

cherry

banana

green

red

yellow

type(color.keys()): <class 'dict_keys'>

type(color.values()): <class 'dict_values'>

type(color.items()): <class 'dict_items'>

{'apple': 'green', 'cherry': 'red', 'banana': 'yellow'}

list(color.keys()): ['apple', 'cherry', 'banana']

color: {'apple': 'green', 'banana': 'yellow'}

color: {}

s: {'num': (3, 4, 5), 'age': 40.5, 'job': [1, 2, 3], 'name': {'Cho': 1, 'kim': 2}, 'set': {1, 2, 3}}

type(s): <class 'dict'>

isRight: False type(isRight): <class 'bool'>

1 < 2: True

1 != 2: True

1 is not 2: True

1 == 2: False

1 is 2: False

True and True: True

True & True: True

True & False: False

True or False: True

True | False: True

not False: True

bool(0): False

bool(-1): True

bool('test'): True

bool(None): False

a: [38, 2, 3] b: [38, 2, 3]

id(a): 4302873992 id(b): 4302873992

c: [1, 2, 3] d: [1, 2, 3]

id(c): 4302937288 id(d): 4302874632

c: [38, 2, 3] d: [1, 2, 3]