python学习手册13 :while及for循环

#!/usr/bin/env python
# -*- coding:utf8 -*-
# Import python libs
from __future__ import print_function

for x in ["spam", "eggs", "ham"]:
    print(x, end='\n')

sum=0
for x in [1,2,3,4]:
    sum +=x
print(sum)
prod=1
for item in [1,2,3,4]:
    prod*=item
print(prod)
#for循环应用于字符串，元组
S='asdfafafdag[4qqqfqf'
T=("a","b","c")
for x in S:
    print(x,end=',')

for y in T:
    print(y,end='_')

Y=((1,2),(3,4),(5,6))
for (a,b) in Y:
    print (a,b)

D={'a':1,'b':2,'c':3}
print(list(D.items()))
L=list(D.items())
print(L)
for (key,value) in D.items():
    print(key, '=>', value)
((a,b),c) = ((1,2),3)
print(a,b,c)
for ((a,b),c) in [((1,2),3),((4,5),6)]:
    print(a,b,c)
all = (1,2,3,4)
#a,*b,c=(1,2,3,4)
a,b,c=all[0],all[1:3],all[3]
print(a,b,c)


items=['aaa',111,(4,5),2.01]
tests=[(4,5),3.14]
for key in tests:
    for item in items:
        if key == item:
            print(key,'was found.')
            break
    else:
        print(key,'was not found.')
for key in tests:
    if key in items:
        print(key,'was found.')
    else:
        print(key,'was not found.')
seq1='adfklo2'
seq2='aqwerl2'
res=[]
for x in seq1:
    if x in seq2:
        res.append(x)
print(res)
print(range(5))
print(range(2,100,2))
print(range(10,-5,-1))
print(range(-5,5,2))
for i in range(-10,50,2):
    print(i,':line')
X='fghjkl;'
for i in range(len(X)):
    print(X[i],end=',')
for i in X:
    print(i,end='.')
print('================')
Y='asdfghjklwertyuiodfghjkertyu'
for i in range(0,len(Y),3):
    print(Y[i],';')
print(Y[::4])
Z=[1,2,3,4,5]
for i in range(len(Z)):
    Z[i]+=1
print(Z)
A=[10,20,30,40,50]
B=[1,2,3,4]
print(zip(A,B))
for (i,j) in zip(A,B):
    print(i,'+',j,'=',i+j)

C=['ADF','WER','HKL']
D=[1,2,3]
E={}
for k,v in zip(C,D):
    E[k]=v
print(E)
E=dict(zip(C,D))
print(E)
#产生偏移和元素：enumerate
S='asdfghjkl'
for offset,item in enumerate(S):
    print(item,'appears at offset',offset)
'''
a appears at offset 0
s appears at offset 1
d appears at offset 2
f appears at offset 3
g appears at offset 4
h appears at offset 5
j appears at offset 6
k appears at offset 7
l appears at offset 8
'''
#依次取出
E=enumerate(S)
print(next(E))
print(next(E))
print(next(E))
print(next(E))
print(next(E))
print(next(E))
print(next(E))
print(next(E))
print(next(E))
'''
(0, 'a')
(1, 's')
(2, 'd')
(3, 'f')
(4, 'g')
(5, 'h')
(6, 'j')
(7, 'k')
(8, 'l')
'''
#生成与偏移的相对应的个数的元素
print([a * b for a,b in enumerate(S)])
'''
['', 's', 'dd', 'fff', 'gggg', 'hhhhh', 'jjjjjj', 'kkkkkkk', 'llllllll']
'''