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/python3from 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))