def add(a, b):
    return a+b

print add(1, 2)
print

def myabs(x):
    if x < 0 : 
        x = -x
    return x

print abs(-4)
print myabs(-4)

def add(a, b):
    return a + b

print add

c = add(10, 30)
print c

f = add
print f(4, 5)

print f

print f is add

def simpleFunction():
    pass

simpleFunction()

def addmember(members, newmember):
    if newmember not in members:   # 기존 멤버가 아니면
        members.append(newmember)  # 추가

members = ['hwang', 'lee', 'park', 'youn']  # 리스트에 초기 멤버 설정

addmember(members, 'jo')  # 새로운 멤버 추가

addmember(members, 'hwang') # (이미 존재하는) 새로운 멤버 추가

print members

def f1(b):
    b = 100

a = 200
f1(a)
print a

def f2(b):
    b = "abc"

a = "def"
f2(a)
print a

def f3(b):
    b = (1,2,3)

a = (4,5,6)
f3(a)
print a

def f4(b):
    b[1] = 10

a = [4,5,6]
f4(a)
print a

def f5(b):
    b['a'] = 10

a = {"a":1, "b":2}
f5(a)
print a

def nothing():
    return

print nothing()

def print_menu():
    print '1. Snack'
    print '2. Snake'
    print '3. Snick'
    
print_menu()

a = print_menu()

print a

def abs(x):
    if x < 0 : return -x
    return x

print abs(-10)

def swap(x, y):
    return y, x   # 튜플로 리턴된다.

a = 10
b = 20
print a, b
print 

a, b = swap(a, b) # 결과적으로 a, b = b, a와 동일
print a, b
print

a = 10
b = 20
x = swap(a, b)
print x[0], x[1]  # 하나의 이름으로 튜플을 받아서 처리할 수 도있다.

def length_list(l):
    res = []
    for el in l:
        res.append(len(el))
    return res

l = ['python', 'pyson', 'pythong', 'pydon']
print length_list(l)

l = ['python', 'pyson', 'pythong', 'pydon']
print [len(s) for s in l]

def add(a, b):
    return a + b

c = add(1, 3.4)
d = add('dynamic', 'typing')
e = add(['list'], ['and', 'list'])
print c
print d
print e

def incr(a, step=1):
    return a + step

b = 1
b = incr(b)     # 1 증가
print b

b = incr(b, 10) # 10 증가
print b

def incr(step=1, a):
    return a + step

def incr(a, step=1, step2=10):
    return a + step + step2

print incr(10)

def area(height, width):
    return height * width

#순서가 아닌 이름으로 값이 전달
a = area(height='height string ', width=3)
print a

b = area(width=20, height=10)
print b

print area(20, width=5)

area(width=5, 20)

def incr(a, step=1, step2=10, step3=100):
    return a + step + step2 + step3

print incr(10, 2, step2=100)

def incr(a, step=1, step2=10, step3=100):
    return a + step + step2 + step3

print incr(10, 2, step2=100, 200)

def incr(a, step=1, step2=10, step3=100):
    return a + step + step2 + step3

print incr(10, 2, step2=100, step3=200)

def varg(a, *arg):
    print a, arg

varg(1)
varg(2,3)
varg(2,3,4,5,6)

def printf(format, *args):
    print format % args

printf("I've spent %d days and %d night to do this", 6, 5)

def h(a, b, c):
    print a,b,c
    
args = (1, 2, 3)
h(*args)

dargs = {'a':1, 'b':2, 'c':3}
h(**dargs)