[Python] 파이썬 함수

 1. 함수 (def) 

def f(x):
    y = 2 * x + 3
    return y

y1 = f(1)

print('y1: ', y1)

 

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 2. 함수 유형 (1) 

def type1(x, y):
    z = x + y
    return z

rs1 = type1(1, 2)
print('rs1: ',rs1)

 

 3. 함수 유형 (2) 

def type2(dataset):
    tot = 0
    for data in dataset:
        tot += data
    print('dataset 합: ', tot)
    
type2([1,2,3,4,5])
type2((2,4,6,8,10))

 

 4. 함수 유형 (3) 

def type3():
    dataset = [n for n in range(11)]
    tot = 0
    for k in dataset:
        tot += k
    return tot
    
rs3 = type3()
print('rs3: ',rs1)

 

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 5. 디폴트 매개변수 

def hello(name='홍길동', age=20):
    print('이름: ', name)
    print('나이: ', age)

hello()
hello('김유신')
hello('김춘추', 25)

 

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 6. 가변 매개변수  

# 가변 매개변수 (*items: 매개변수 값 개수 무관 list개념) (java: items...)
def total(*items):
    tot = 0
    for i in items:
        tot += i
    return tot

rs1 = total(1)
rs2 = total(1,2)
rs3 = total(1,2,3)
rs4 = total(1,2,3,4)
rs5 = total(1,2,3,4,5)

print('rs1: ', rs1)    
print('rs2: ', rs2)    
print('rs3: ', rs3)    
print('rs4: ', rs4)    
print('rs5: ', rs5)

 

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 7. 하나 이상의 값을 리턴  

def sumMulti(n1, n2):
    y1 = n1 + n2
    y2 = n1 * n2
    return y1, y2

r1, r2 = sumMulti(2,3)

print('r1 : ', r1)
print('r2 : ', r2)

 

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 8. 변수에 저장하는 함수 

def plus(x, y):
    return x + y

def minus(x, y):
    return x - y

var1 = plus
var2 = minus

r1 = var1(1, 2)
r2 = var2(2, 3)

print('r1 : ', r1)
print('r2 : ', r2)

 

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 9. 함수 리스트 

def plus(x, y):
    return x + y

def minus(x, y):
    return x - y

defs = [plus, minus]
r1 = defs[0](1,2)
r2 = defs[1](2,3)

print('r1 : ', r1)
print('r2 : ', r2)

 

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 10. 람다 함수 

f1 = lambda x, y : x + y
f2 = lambda x, y : x - y

r1 = f1(1,2)
r2 = f1(2,3)

print('r1 : ', r1)
print('r2 : ', r2)