Python 实用小技巧

一：for循环和if-else结合

1：一行实现双层循坏

# 循环遍历 [[],[],[]]
list_a = [['Chris Pratt', ' Vin Diesel', ' Bradley Cooper', ' Zoe Saldana'], ['Noomi Rapace', ' Logan Marshall-Green', ' Michael Fassbender', ' Charlize Theron']]

list_b = [i for j in list_a for i in j]
print(list_b)

# ['Chris Pratt', ' Vin Diesel', ' Bradley Cooper', ' Zoe Saldana', 'Noomi Rapace', ' Logan Marshall-Green', ' Michael Fassbender', ' Charlize Theron']

 2：一行实现for-与if-else逻辑

a = [i if i >1 else 8 for i in [8,9,7]]               #  
b= [ i for i in [0,1,2,3] if i >0]                      # 只有if时要写在后面
print(a)
print(b)

 3：Facebook 景霄-07条件与循环_思考题

　　ps:一行或多行实现 aim_list

attributes = ['name', 'dob', 'gender']
values = [['jason', '2000-01-01', 'male'],['mike', '1999-01-01', 'male'],['nancy', '2001-02-01', 'female']]

# expected outout:
aim_list = [{'name': 'jason', 'dob': '2000-01-01', 'gender': 'male'},{'name': 'mike', 'dob': '1999-01-01', 'gender': 'male'},{'name': 'nancy', 'dob': '2001-02-01', 'gender': 'female'}]


#  一行
one = [dict(zip(attributes,value)) for value in values ]

#  多行
more = []
temp = {}
for index,value in enumerate(values):
    temp[attributes[index]] = value[index]
    more.append(temp)
print('one:',one)
print('more:',more)