python中的list 查找与过滤方法整合

3 in [1, 2, 3] # => True

matches = [x for x in lst if fulfills_some_condition(x)]
matches = (x for x in lst if x > 6)

matches = filter(fulfills_some_condition, lst)

next(x for x in lst if ...)

next((x for x in lst if ...), [default value])

[1,2,3].index(2) # => 1
[1,2,3].index(4) # => ValueError

[1,2,3,2].index(2) # => 1

[i for i,x in enumerate([1,2,3,2]) if x==2] # => [1, 3]

list=[{'id': '2', 'position': [3148.18, 4142.69]},{'id': '1', 'position': [3148.19, 142.69]}]

list[next(index for (index, d) in enumerate(list1) if d["id"] == '2')]['position']

#列表过滤的几种方法
#过滤大于3的元素
 
#1.利用循环
def filterList1(*lst):
    b=[]
    for i in lst:
        if i>3:
            b.append(i)
    return b
 
f1=filterList1(1,2,3,4,5,6)
print(f1)
 
#2.利用列表内计算
def filterList2(*lst):
    b=[i for i in lst if i >3]#列表解析
    return b
f2=filterList2(1,2,3,4,5,6)
print(f2)
 
#3.利用filter
def filterList3(*lst):
    b=filter(lambda x:x>3,lst)
    return b
f3=filterList3(1,2,3,4,5,6)
print(list(f3))#注意此句。