python如何查找列表元素

如果你想坚持你的模式,这是一个选择:

search = {'Age' : 21, 'Gender' : 'M'}

idxs = [ (main_col.index(key), val) for key, val in search.items()]

tmp = [ set(tuple(person) for person in main_row if person[i] == v) for i, v in idxs ]

res = set.intersection(*tmp)

#=> {('Wade', 21, 'M'), ('Malcom', 21, 'M')}

注:

我用过

intersection

AND

,但您可以自定义上可用的任何操作

set

https://docs.python.org/3.7/library/stdtypes.html#set

):

union

,

交叉

difference

, ...

您可以转换为方便的方法:

def lookup(search, main_row, main_col):

idxs = [ (main_col.index(key), val) for key, val in search.items()]

tmp = [ set(tuple(person) for person in main_row if person[i] == v) for i, v in idxs ]

return set.intersection(*tmp)

lookup({'Age' : 21}, main_row, main_col)

#=> {('Wade', 21, 'M'), ('Mellisa', 21, 'F'), ('Malcom', 21, 'M')}

lookup({'Age' : 21, 'Gender' : 'M'}, main_row, main_col)

#=> {('Malcom', 21, 'M'), ('Wade', 21, 'M')}

lookup({'Age' : 21, 'Gender' : 'M', 'Name': 'Malcom'}, main_row, main_col)

#=> {('Malcom', 21, 'M')}

main_row = [['Peter', 18, 'M'], ['Sam', 20, 'M'], ['Carol', 19, 'F'], ['Malcom', 21, 'M'], ['Oliver', 25, 'M'], ['Mellisa', 21, 'F'], ['Minreva', 18, 'F'], ['Bruce', 23, 'M'], ['Clarke', 24, 'M'], ['Zuck', 22, 'M'], ['Slade', 23, 'M'], ['Wade', 21, 'M'], ['Felicity', 22, 'F'], ['Selena', 23, 'F'], ['Ra\'s Al Gul',700, 'M'], ['Oliver', 31, 'M']]

这就构成了字典

people

,将头的第一个列表分开:

people = [ {'name':name, 'age':age, 'gender':gender} for name, age, gender in main_row]

#=> [{'name': 'Peter', 'age': 18, 'gender': 'M'}, {'name': 'Sam', 'age': 20, 'gender': 'M'}, ....

next(person for person in people if person['name'] == 'Oliver' and person['age'] == 31 )

#=> {'name': 'Oliver', 'age': 31, 'gender': 'M'}

the_21_years_old = [ person for person in people if person['age'] == 21 ]

#=> [{'name': 'Malcom', 'age': 21, 'gender': 'M'}, {'name': 'Mellisa', 'age': 21, 'gender': 'F'}, {'name': 'Wade', 'age': 21, 'gender': 'M'}]

您可以对返回的“记录”执行任何需要的操作:

for person in the_21_years_old:

print(person['name'], person['age'])

# Malcom 21

# Mellisa 21

# Wade 21