2.3 字符串操作
1、使用制表符或者换行符来添加空白
print("\tPython\tc\tjava\truby\tmysql\n\tsql\tscala\tr\tperl\toracle")
2、删除空白
确保字符串末尾没有空白，可使用方法rstrip()，剔除字符串开头的左边的空格用lstrip()，同时剔除字符串两端的空白用strip()，类似于SQL中的trim()函数。
动手试一试：
name="Eric Green"
print('"Hello '+name+',would you like to learn some Python today?"')
print(name.lower())
print(name.upper())
print(name.title())
print('Albert Einstein once said,“A person who never made a miatake never tried anything new.”')
第3章 列表简介
列表是由一系列按特定顺序排列的元素组成。
1、在列表末尾添加元素
motorcycles=[]
motorcycles.append('one')
2、在列表中插入元素
motorcycles.insert(0,'one')
3、从列表中删除元素
del motorcycles[0]
pop()删除列表末尾的元素
pop(0,1,2)弹出列表中任何位置处的元素
4、根据值删除元素
motorcycles.remove('one')
动手试一试：
#3-4嘉宾名单
guests=['peng','dad','mom','grandmother','shishi']
for guest in guests:
print('Dear '+guest.title()+',I invite you to dinner!')
print('Peng,she can\'t come!')
#del guests[0]
#guests.insert(0,'qingquan')
guests[0]='qingquan'
for guest in guests:
print('Dear '+guest.title()+',I invite you to dinner!')
print('I\'m so happy that I found a bigger table for dinner!')
guests.insert(0,'ting')
guests.insert(3,'long')
guests.append('zuo')
for guest in guests:
print('Dear '+guest.title()+',I invite you to dinner!')
print('I\'m so sad that dinner only for two!')
pop1=guests.pop()
print(pop1.title()+',I\'m sorry for that I can\'t invite you tonight!')
pop2=guests.pop()
print(pop2.title()+',I\'m sorry for that I can\'t invite you tonight!')
pop3=guests.pop()
print(pop3.title()+',I\'m sorry for that I can\'t invite you tonight!')
pop4=guests.pop()
print(pop4.title()+',I\'m sorry for that I can\'t invite you tonight!')
pop5=guests.pop()
print(pop5.title()+',I\'m sorry for that I can\'t invite you tonight!')
pop6=guests.pop()
print(pop6.title()+',I\'m sorry for that I can\'t invite you tonight!')
for guest in guests:
print('Dear '+guest.title()+',I invite you to dinner!')
del guests[0]
del guests[0]
print(guests)
3.3 组织列表
1、使用方法sort()对列表进行永久性排序
cars.sort()
cars.sort(reverse=True)
2、使用函数sorted()对列表进行临时排序
print(sorted(cars))
3、倒着打印列表 临时性
cars.reverse()
恢复再用一次reverse()
4、确定列表的长度
函数len(cars)
动手试一试：
#3-8 放眼世界
places=['the South Pole','Maldives','Europe','USA','Japen']
print(places)
print(sorted(places))
print(places)
print(sorted(places,reverse=True))
print(places)
places.reverse()
print(places)
places.reverse()
print(places)
places.sort()
print(places)
places.sort(reverse=True)
print(places)
第4章 操作列表
4.1、遍历整个列表
for magician in magicians:
print(magician)
#注意缩进
动手试一试：
#4-1 披萨
pizzas=['chicken','fish','beaf']
for pizza in pizzas:
print('I like '+pizza+' pizza.')
print('I really love pizza!')
4.3 创建数值列表
1、使用函数range()创建数字列表
numbers=list(range(1,6))
range(2,11,步长2)
for value in range(1,11):
squares.append(value**2)
列表解析
上面的代码等价于 squares=[value**2 for value in range(1,11)]
动手试一试：
#4-3 数到20
for value in range(1,21):
print(value)
numbers=list(range(1,1000001))
#for number0 in numbers:
# print(number0)
print(min(numbers))
print(max(numbers))
print(sum(numbers))
odds=list(range(1,21,2))
for odd0 in odds:
print(odd0)
threes=list(range(3,31,3))
for three0 in threes:
print(three0)
cubes=[]
for value in range(1,11):
cubes.append(value**3)
print(cubes)
cubes_new=[value**3 for value in range(1,11)]
print(cubes_new)
4.4使用列表的一部分
1、切片
列表的部分元素
players[XX:XX]
2、复制列表
friend_foods=my_foods[:] 使用切片复制列表
动手试一试：
#4-10 切片
pizzas=['chicken','fish','beaf','duck','fruit']
for pizza1 in pizzas[0:3]:
print('The first three items in the list are:'+pizza1 )
for pizza2 in pizzas[1:4]:
print('three items from the middle of the list are:'+pizza2 )
for pizza3 in pizzas[-3:]:
print('The last three items in the list are:'+pizza3 )
odds=list(range(1,21,2))
for odd3 in odds[0:3]:
print('The first three items in the list are:'+str(odd3) )
pizzas=['chicken','fish','beaf']
friend_pizzas=pizzas[:]
pizzas.append('duck')
friend_pizzas.append('fruit')
for pizza in pizzas:
print('My favorite pizzas are:'+pizza)
for friend_pizza in friend_pizzas:
print('My friend\'s favorite pizzas are:'+friend_pizza)
4.5 元组：不可变的列表
定义元组：dimensions=(200,50)
不可改变元组的元素，可以给存储元组的变量赋值。
