python如何在列表、字典中筛选数据

#!/usr/bin/python3
 
 
def filter_l(data):
  res = []
  for i in data:
    if i > 0:
      res.append(i)
  return res
 
if __name__ == '__main__':
  data = [3, 9, -1, 10, -2]
  new_l = filter_l(data)
  print(new_l)

#!/usr/bin/python3
 
from random import randint
 
 
def filter_l(data):
  # 循环data列表，把值一个一个取出 交个lambda中x，如何lambda函数为True，返回x生成一个新的filter对象
  return filter(lambda x: x >= 0, data)
 
if __name__ == '__main__':
  # 列表生成10个 -10 到 10 的随机数
  data = [randint(-10, 10) for _ in range(10)]
  print(data)
  # new_l 为可迭代对象
  new_l = filter_l(data)
  print(list(new_l), type(new_l))

#!/usr/bin/python3
 
from random import randint
 
 
def filter_l(data):
  # 循环data列表，把值一个一个取出 是否满足if条件，满足True返回x生成一个新列表
  return [x for x in data if x >=0 ]
 
if __name__ == '__main__':
  # 列表生成10个 -10 到 10 的随机数
  data = [randint(-10, 10) for _ in range(10)]
  print(data)
  # new_l 为可迭代对象
  new_l = filter_l(data)
  print(list(new_l), type(new_l))

#!/usr/bin/python3
 
from random import randint
 
 
def filter_l(data):
  print(data.items())
  # 把字典转换成dict_items，循环里面的key和value，满足if条件返回对应的key和value值
  return {k: v for k, v in data.items() if v > 90}
 
if __name__ == '__main__':
  # 字典生成式
  data = {x: randint(0, 100) for x in range(10)}
  print(data)
  new_l = filter_l(data)
  print(new_l, type(new_l))

#!/usr/bin/python3
from random import randint
 
 
def filter_l(data):
  # 迭代集合中值，满足条件为True返回x
  return {x for x in data if x % 3 == 0}
 
if __name__ == '__main__':
  # 集合生成式
  data = {randint(0, 100) for x in range(10)}
  print(data)
  new_l = filter_l(data)
  print(new_l, type(new_l))