python基础

程传纪20190221

a=‘abc123c45’

he=0

for i in a:

if ‘0’<=i<=‘9’:

he=he*10+ord(i)-48

print(he)

#============================
#求字符里数字的和

a=‘ab2c123c45’

i=0

he=0

while i<len(a):

if a[i]>= ‘0’ and a[i]<=‘9’:

he=he*10+int(a[i])

i+=1

print(he)

#元祖

a=(1,2,3,4)

print(type(a))#tuple元祖，切不可更改

for i in a:

print(i)

for i in a:

print(i)

a=(1,2,3,4,5,6,7,8)

i=0

while i<len(a):

print(‘第{}个数是{}’.format(i+1,a[i]),end=’,’)

i+=1

a=(1,2,3,4,5)

i=0

while i<len(a):

print(‘第%d个数是%d’%(i+1,a[i]))

i+=1

#======================================================

a=(1,2,3,4,5,6,7)

print(a[8:0:-1])

a=(1,2,3,4,5,6,7)

print(a[-2:-6:-1])

i=(1,2,3)

print(type(i))

j=(1)#

print(type(j))#输出的是int

k=(1,)

print(type(k))#输出的是tup元祖类型，当括号里只有一个元素时，加，是元祖，不加是数字

#=========================================

i,j=(1,)

print(i)

print(j)

#=================================

i=(1,2,3)

j=[4,5,6]

# i.extend(j),不能把列表添加到元组里，因为元祖不能修改

j.extend(i)

print(j)

=======================================

#解析列表里的列表

a=[[1,2,3],[4,5,6],[7,8,9],[‘a,’‘b,’‘c’]]

i=0

while i<len(a):

j=0

while j<len(a[i]):

print(a[i][j],end=’’)

j+=1

print()

i+=1

a=[[1,2,3],[4,5,6],[7,8,9],[‘a,’‘b,’‘c’]]

i=0

while i<len(a):

for j in a[i]:

print(j,end=’ ')

print()

i+=1

for i in a:

j=0

while j<len(i):

print(i[j],end=’’)

j+=1

print()

for i in a:

for j in i:

print(j,end=’’)

print()

#练习===========================

for date in a:

i=0

while i<len(date):

print(date[i],end=’ ')

i+=1

print()

#=---------------------------------------

i=0

while i<len(a):

j=0

while j<len(a[i]):

print(a[i][j],end=’ ')

j+=1

i+=1

print()

#---------------------------------------

i=0

while i<len(a):

for j in a[i]:

print(j,end=’ ')

i+=1

print()

#-----------------------------------------------

for i in range(len(a)):

for j in range(len(a[i])):

print(a[i][j],end=’’)

print()

#-------------------------------------------

for i in range(len(a)):

for j in range(len(a[i])):

print(a[i][j],end=’ ')

print()

#=====================================
#字典由键和值来表示

a={‘name’:‘张三’,‘age’:18,‘address’:‘河北’}

print(a[‘name’])

print(a)

print(a[‘age’])

print(a[‘address’])

a={‘name’:‘张三’,‘age’:18,‘address’:‘河北’}

a[‘sex’]=‘fale’

print(a)

a[‘address’]=‘山东’

a[‘sex’]=‘male’

print(a)

#字典是可以增加，修改,删除只能用del pop

a={‘name’:‘张三’,‘age’:18,‘address’:‘河北’}

del(a[‘name’])

print(a)

a.pop(‘name’)

print(a)

#------------------------------------------------------

i=dict(name=‘李四’,age=18,address=‘北京’)

print(i[‘name’])#输出键name地值李四

i[‘sex’]=‘nan’#增加一个元素’sex’: ‘nan’

print(i)

#--------------------------------------------------

i=dict(name=‘李四’,age=18,address=‘北京’)

print(i.get(‘age’,‘age’))获取字典里键对应的值

print(i.get(‘sex’,‘zhubajie’))#没有的，后面的值替代

print(i.get(‘age’,‘ddddd’))

print(i)

李处字典里的键

i=dict(name=‘李四’,age=18,address=‘北京’)

print(i.keys())#keys值所有的键

for key in i.keys():

print(i.get(key))

print(i.values())#values输出字典里面的值

for k in i.values():

print(k)

#----------------

i={‘name’:‘张三’,‘age’:‘28’,‘address’:‘北京’}

print(i.items())

for k, v in i.items():

print(k,v)

#---------------------------

i={‘name’:‘张三’,‘age’:‘28’,‘address’:‘北京’}

# print(i.pop(‘name’))

# print(i)

print(i.popitem())#popitem删除最后一个

print(i)

#-------------------------------

#字符串

i=‘hello’*5

j='hello '+'world '+"!"

print(i)

print(j)

#-----------------------------
i={
‘001’:{‘name’:‘张三’,‘age’:‘18’,‘adress’:‘北京’},
‘002’:{‘name’:‘李四’,‘age’:‘28’,‘adress’:‘南京’},
‘003’:{‘name’:‘王五’,‘age’:‘38’,‘adress’:‘北京’}
}

for key1 in i.keys(): # 把字典i里所有的键拿出来

print(key1, end=’’)

for key2 in i[key1]: # i[key1]是i里面key1对应的值，key2指的是i里面的值的键

print(key2, i[key1][key2], end=’’) # i[key1][key2]指的是字典i里值里的值

if (i[key1][‘adress’]) == ‘北京’:

i[key1][‘house’] = ‘1000’

print(i)

print()

#-----------------------------------------------------

for k ,v in i.items():#k代表的是里面的键，代表值，items代表字典里所有有的项目

print(k,end=’’)

for m,n in v.items():

print(m,n,end=’’)

print()

#-----------------------------
#在字典里凡是地址为北京的加上house，10000

for k in i.keys():

if i[k][‘adress’]==‘北京’:

i[k][‘house’]=10000

print(i)