当前位置:首页 > 联系方式 >

Python 入门教程 9 ---- A Day at the Supermarket

作者:永年县聚联紧固件制造有限公司    发布时间:2017-09-09 10:30:02

Python 入门教程 9 ---- A Day at the Supermarket 第一节

1 介绍了for循环的用法

for variable in values:

statement

2 for循环打印出列表的每一项

for item in [1 , 2 , 3]:

print item

那么将打印出1,2,3

3 练习:使用for循环,把列表中的每一项打印出来

[python]

names = ["Adam","Alex","Mariah","Martine","Columbus"]

# use for loop

for str in names:

print str

第二节

1 介绍了我们可以使用for循环打印出字典中的每一个key

2 比如这个例子,我们可以打印出key为foo的value值为bar

[python]

# A simple dictionary

d = {"foo" : "bar"}

for key in d:

# prints "bar"

print d[key]

3 练习:打印出字典webster的所有key对应的value

[python]

webster = {

"Aardvark" : "A star of a popular children's cartoon show.",

"Baa" : "The sound a goat makes.",

"Carpet": "Goes on the floor.",

"Dab": "A small amount."

}

# Add your code below!

for key in webster:

print webster[key]

第三节

1 介绍了for里面我们可以添加if/else语句来判断

2 比如

[python]

for item in numbers:

if condition:

# Do something

3 练习:只输出列表中的7个数

[python]

a = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13]

for num in a:

if(a < 7):

print a

第四节

1 介绍了在函数里面使用for循环

2 练习

1 写一个函数名为fizz_count,参数为列表x

2 函数返回列表中值为"fizz"的个数

[python] view plaincopy

# Write your function below!

def fizz_count(x):

sum = 0

for str in x:

if(str == "fizz"):

sum = sum+1

return sum

第五节

1 练习:把以下的对应关系建立成字典prices

[python]

# the key and values

"banana": 4

"apple": 2

"orange": 1.5

"pear": 3

# you code here

prices = {}

prices["banana"] = 4

prices["apple"] = 2

prices["orange"] = 1.5

prices["pear"] = 3

第六节

1 练习:按照以下的格式输出

[python]

item

price: x

stock: x

# such as

apple

price: 2

stock: 0

[python]

# the first dictionary

prices = {}

prices["banana"] = 4

prices["apple"] = 2

prices["orange"] = 1.5

prices["pear"] = 3

# the second dictionary

stock = {}

stock["banana"] = 6

stock["apple"] = 0

stock["orange"] = 32

stock["pear"] = 15

# you code here

for key in prices:

print key

print "price: "+prices[key]

print "stock: "+stock[key]

第七节

1 练习

1 创建一个列表名叫groceries,有三个值分别为"banana","orange", "apple"

2 写一个函数名叫compute_bill,站群系统,参数是列表food

3 利用循环计算出food中所有物品的总价格

[python]

shopping_list = ["banana", "orange", "apple"]

stock = { "banana": 6,

"apple": 0,

"orange": 32,

"pear": 15

}

prices = { "banana": 4,

"apple": 2,

"orange": 1.5,

"pear": 3

}

# Write your code below!

def compute_bill(food):

sum = 0

for str in food:

sum = sum + prices[str]

return sum

第八节

1 练习

1 创建一个列表名叫groceries,专题系统,有三个值分别为"banana","orange", "apple"

2 写一个函数名叫compute_bill,参数是列表food

3 利用循环计算出food中所有物品的总价格,但是我们在求价格的时候我们一个先判断在stock字典中对应的值是否大于0,如果是的话才进行求和并且把stock对应的value值减一

[python]

shopping_list = ["banana", "orange", "apple"]

stock = { "banana": 6,

"apple": 0,

"orange": 32,

"pear": 15

}

prices = { "banana": 4,

"apple": 2,

"orange": 1.5,

"pear": 3

}

# Write your code below!

def compute_bill(food):

sum = 0

for str in food:

if(stock[str] > 0):

sum = sum + prices[str]

stock[str] = stock[str]-1

return sum

企业建站2800元起,携手武汉肥猫科技,做一个有见地的颜值派!更多优惠请戳:荆州网站建设 http://jingzhou.45qun.com

  • 上一篇:HDU 5389 Zero Escape (MUT#8 dp优化)
  • 下一篇:最后一页
  •