2018.3.14

#一组例子
def demo (newitem,old=[]):
    old.append(newitem)
    return old

print(demo('5',[1,2,3,4]))
print(demo('aaa',['a','b']))
print(demo('a'))
#此处会出现意料之外的情况
print(demo('b'))


def demoo(newitem,old=None):
    if old==None:
        old=[]
    old.append(newitem)
    return old

print(demoo('5',[1,2,3,4]))
print(demoo('aaa',['a','b']))
print(demoo('a'))
print(demoo('b'))

#可变长度参数
def demo(**p):
    for item in p.items():
        print(item)
demo(x=1,y=3,z=5)

def dem(*p):
    for item in p:
        print(item)
dem('q',3,5.4)

E:\Python\python.exe E:/All_Code/python/T_text/text.py
('x', 1)
('y', 3)
('z', 5)
q
3
5.4

f = lambda x,y,z:x+y+z
print(f(2,3,4))
print(f('a','r','f'))

g = lambda x,y=33,z=1:x+y+z
print(g(2,5,5))
print(g(2))

L=[(lambda x:x**2),lambda x:x**3,lambda x:x**4]
print(L[0](2),L[2](2))

import random
def demo(lst):
    m = min(lst)
    result = (m,)
    for index,value in enumerate(lst):
        if value == m:
            result += (index,)
    return result
x = [random.randint(1,20) for i in range(50)]
print(x)
print(demo(x))

#杨辉三角
def demo1(t):
    print([1])
    print([1,1])
    line = [1,1]
    for i in range(2,t):
        r=[]
        for j in range(0,len(line)-1):
            r.append(line[j]+line[j+1])
        line = [1]+r+[1]
        print(line)
demo1(10)

E:\Python\python.exe E:/All_Code/python/T_text/text.py
[3, 2, 4, 2, 8, 8, 19, 20, 10, 15, 9, 19, 5, 14, 14, 13, 2, 2, 1, 17, 13, 18, 17, 4, 9, 4, 6, 16, 8, 7, 7, 7, 
 4, 15, 12, 11, 18, 8, 10, 15, 7, 2, 3, 4, 10, 11, 17, 16, 18, 3]
(1, 18)
[1]
[1, 1]
[1, 2, 1]
[1, 3, 3, 1]
[1, 4, 6, 4, 1]
[1, 5, 10, 10, 5, 1]
[1, 6, 15, 20, 15, 6, 1]
[1, 7, 21, 35, 35, 21, 7, 1]
[1, 8, 28, 56, 70, 56, 28, 8, 1]
[1, 9, 36, 84, 126, 126, 84, 36, 9, 1]