actual case:
1. was filtered off negative listing [3,9, -1,10,20, -2 ..] in
2. Sieve the dictionary { 'LiLei': 79, 'Jim': 88, 'Lucy': 92 ...} value is lower than the entry 90
3. screening the set {77,89,32,20} .. whole element 3 can be out
--- the most common method, the FOR loop iteration, determines if filter plus
E.g:
Write the question: is very verbose in Python, efficiency is very poor!
solution---
List
Liezi:
List comprehension:
'' '
Filter function
filter (,) receives two parameters,
the first, passing a filter function, usually with lambda create an anonymous function
filter function that takes a parameter x, the x is in each list, iterate elements
returns a Boolean value, a Boolean value is false, the element will be discarded
second argument is to filter the list
filter
in the python2.7, will directly return a list
in python3 It will return a generator object
if python3 achieve the correct result in a list, it is necessary:
the generator object, directly to the list builder
** Builder the object is a one-time, if the next has been consumed, the need to re-create
to sum up:
Recommended list comprehension, more simple, no need to create function objects, faster
dictionary:
set
