python：2017.10.31

列表：可修改

a=[1,2,3]
b=[4,5,6]

a+b==[1,2,3,4,5,6]
a*2==[1,2,3,1,2,3]

list('list')==['l','i','s','t']

排序

>>> x=[4,6,2,1,7,9]
>>> x.sort()  # 沒有返回值
>>> x
[1, 2, 4, 6, 7, 9]

>>> y=[4,6,2,1,7,9]
>>> z=sorted(y) # 只有返回值
>>> z
[1, 2, 4, 6, 7, 9]

元組：不可修改

>>> 1,2,3
(1, 2, 3)
>>> (1,2,3)
(1, 2, 3)
>>> (1,)   #必須有逗號
(1,)
>>> (1)
1

字典

>>> items=[('name','Gumy'),('age',16)]
>>> d = dict(items)
>>> d
{'age': 16, 'name': 'Gumy'}
>>> e = dict(name='yc', age=16)
>>> e
{'age': 16, 'name': 'yc'}

people = {
    'yc01':{
        'tele':123,
        'add':'a1b2'
        },#逗號
    'yc02':{
        'tele':312,
        'add':'a2b2'
        }
    }
people['yc01']['add'] #字符串

if

if a>0:
    print 'a>0'
elif a<0:
    print 'a<0'
else:
    print 'a=0'

is 同一性運算符

>>> x=y=[1,2,3]
>>> x is y
True
>>> x.append(4)
>>> x
[1, 2, 3, 4]
>>> y
[1, 2, 3, 4]

當爲同一時，一個修改另外一個也會修改

>>> a=[1,2,3]
>>> b=a[:]
>>> b.append(4)
>>> a
[1, 2, 3]
>>> b
[1, 2, 3, 4]

複製整個切片，完全不同的2個

while

 while x<=3:
    print x
    x += 1

for

 while x<=3:
    print x
    x += 1

>>> numbers = [1,2,3,4]
>>> for number in numbers:
    print number


1
2
3
4

>>> for number in range(0,3):#下限爲0，上限爲3（包括下限，不包括上限）可以沒有下限（默認從0開始）第3個參數爲步長默認爲1
    print number


0
1
2

列表推導式

>>> [x*x for x in range(3)]
[0, 1, 4]

>>> [x*x for x in range(10) if x % 3==0]
[0, 9, 36, 81]