Python基础（1）

#头文件OK
import sys
print(sys.platform)
print (2**100)
x ='spam'
print(x*8)
#input()


#from myfile import title
#print(title)


L=[123,'spam',1.23]
print(len(L))
print(L[0])
print(L[:-1])
L+[4,5,6]
print(L)
L.append('NI') #插入数据
print(L)
print(L.pop(2)) #删除下标为2元素
print("插入后：",L)


#--------------------------------------
print("############################")
m = ["bb","aa","cc"]
m.sort()    #正排序
print("正排序：",m)
m.reverse()  #反排序
print("反排序:", m)




#----------------嵌套--------------------
Yin = [[1,2,3],
       [4,5,6],
       [7,8,9]]
print("嵌套",Yin)
print(Yin[1])
print(Yin[1][2])




#-----------------------列表解析-----------------------------
col2 =[row[1] for row in Yin]
print(col2)


print([row[1]+1 for row in Yin])
print([row[1] for row in Yin if row[1]%2 == 0])


diag = [Yin[i][i] for i in[0,1,2]]
print(diag)


doubles = [c*2 for c in 'spam']
print(doubles)


G =(sum(row) for row in Yin)
print(next(G))


print(list(map(sum,Yin)))
print({sum(row)for row in Yin})
print({i:sum(Yin[i]) for i in range(3)})
#----------------列表，集合，字典 解析--------------------------
hy=[ord(x) for x in 'spaam']
print("列表:",hy)
hy2= {ord(x) for x in 'spaam'}
print("集合：",hy2)
hy3 ={x:ord(x) for x in 'spaam'}
print("字典：",hy3)
#--------------------------字典-------------------------------
D ={'food':'spam','a':4,'color':'dd'}
print(D)
print(D['food'])
D['a']+=1
print(D)
#--------------------字典(重访嵌套)------------------------------
print("-------------------字典(重访嵌套)-----------------------")
chend ={}
chend['name'] = 'Bob'
chend['job'] = 'dev'
chend['age'] = 40
print(chend)
rec = {'name' :{'rirst:':'Bob','last':'amith'},
       'job':['dev','mgr'],
       'age':40.5}
print("name:",rec['name'])
print("rec[name]['last']:",rec['name']['last'])
rec['job'].append('janitor')
print(rec)
print("-------------------字典(键值)-----------------------")
ks= list(D.keys())
print(ks)
ks.sort()
print(ks)
#--------------------for------------------------------
for key in ks:
    print(key,'=>' ,D[key])
for key in sorted(D):  #sorted 对各种对象进行排序
    print(key,'=>',D[key])
for c in 'spam':
    print(c.upper())   #upper 把每一个字符转换成大写
#--------------------while------------------------------
x =4
while x > 0:
    print('spam!'*x)
    x -=1
#数字平方根 方法-：
squares = [x**2 for x in[1,2,3,4,5]]
print(squares)
#数字平方根 方法二：
forsquares =[]
for x in [1,2,3,4,5]:
    forsquares.append(x**2)
print(squares)
#数字平方根（for总结）如map与filter 把for(快两倍左右)
#查找键值
'name' in rec
if not 'nam' in rec:
    print("missing")
value = rec.get('name',0)
print(value)
value = rec['name'] if 'name' in rec else 0
print(value)
#--------------------元组------------------------------
print("--------------------元组------------------------------")
T =(1,2,3,4)
print(len(T))
#a= T+(5,6)


print(T.index(4))
print(T.count(2))


class worker:
    def _init_(self,name,pay):
        self.name = name
        self.pay = pay
    def lastName(self):
        return self.name.split()[-1]
    def giveRaise(self,percent):
        self.pay *= (1.0 + percent)
        
jjjjj = worker('Bob smith',50000)


#print(bob)
#sue = worker('sue jones',60000)
#print(sue)
#bob.lastname()
#print(bob)
#sue.lastneme()
#print(sue)
#sue.giveRaise(.10)
#print(sue)
#sue.pay
#print(sue)
#--------------------文件操作------------------------------
f = open('data.txt','w')
f.write('Hello\n')
f.close()
#--------------------自定义类------------------------------