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

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

# 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

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

for item in numbers:
if condition:
# Do something

3 练习:只输出列表中的7个数

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

# 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

# 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

item
price: x
stock: x
# such as
apple
price: 2
stock: 0
# 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,参数是列表food

3 利用循环计算出food中所有物品的总价格

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,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

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
04-26 23:54