有的時候使用dir(Module)，可以檢視裡面的方法，但是模組自帶的屬性"__"開頭的也會顯示，如下:

>>> import random
>>> dir(random)
['BPF','LOG4','NV_MAGICCONST','RECIP_BPF','Random','SG_MAGICCONST','SystemRandom','TWOPI','WichmannHill','_Buil
tinMethodType','_MethodType','__all__','__builtins__','__doc__','__file__','__name__','__package__','_acos','_c
eil','_cos','_e','_exp','_hashlib','_hexlify','_inst','_log','_pi','_random','_sin','_sqrt','_test','_test_
generator','_urandom','_warn','betavariate','choice','division','expovariate','gammavariate','gauss','getrandbi
ts','getstate','jumpahead','lognormvariate','normalvariate','paretovariate','randint','random','randrange','sam
ple','seed','setstate','shuffle','triangular','uniform','vonmisesvariate','weibullvariate']
>>>

這個時候想過濾以"_"或"__"開頭的方法，可以:

>>> filter(lambda s: not s.startswith("_"),dir(random))
['BPF','betav
ariate','getrandbits','lognormv
ariate','sample','t
riangular','weibullvariate']
>>>

從上面來看，使用filter()函式，結合lambda函式很好的完成了任務。 其他的例子，比如想從一個列表中過濾非數字的字串列表:

>>> L = ["1234","ABCD","BOOK"]
>>> filter(lambda s: s.isdigit(),L)
['1234']
>>>

補充知識：python不同長度列表，對應合併

1. 說明

lis1 = [{‘OS_bit': u'64 \u4f4d',‘OS_version': ‘10.0.10240',‘OS_name': u'Microsoft Windows 10 \u4f01\u4e1a\u7248 2015 \u957f\u671f\u670d\u52a1\u65b9\u6848'}]
lis2 = [{‘ip':‘10.20.122.32'}]
lis3 = [{‘CPU_name': u'Intel® Core™ i5-4200H CPU @ 2.80GHz'}]
lis4 = [{‘memory_size': ‘1600MHz',‘memory_name': u'Physical Memory 0'},{‘memory_size': ‘1600MHz',‘memory_name': u'Physical Memory 2'}]
lis5 = [{‘GPU_name': u'NVIDIA GeForce GTX 950M',‘GPU_size': ‘2G'},{‘GPU_name': u'Intel® HD Graphics 4600',‘GPU_size': ‘1G'}]

有這五個列表，要求合併成一個列表，並且所有列表的第一元素放在新列表的第一元素，以此類推。

2. 程式碼

# !/usr/bin/env/python
# _*_coding:utf-8_*_
# Data:2019-04-10
# Auther:蘇莫
# Link:QQ2388873062
# Address:https://blog.csdn.net/lingluofengzang
# PythonVersion:python2.7

import sys

reload(sys)
sys.setdefaultencoding('utf-8')

lis1 = [{'OS_bit': u'64 \u4f4d','OS_version': '10.0.10240','OS_name': u'Microsoft Windows 10 \u4f01\u4e1a\u7248 2015 \u957f\u671f\u670d\u52a1\u65b9\u6848'}]
lis2 = [{'ip':'10.20.122.32'}]
lis3 = [{'CPU_name': u'Intel(R) Core(TM) i5-4200H CPU @ 2.80GHz'}]
lis4 = [{'memory_size': '1600MHz','memory_name': u'Physical Memory 0'},{'memory_size': '1600MHz','memory_name': u'Physical Memory 2'}]
lis5 = [{'GPU_name': u'NVIDIA GeForce GTX 950M','GPU_size': '2G'},{'GPU_name': u'Intel(R) HD Graphics 4600','GPU_size': '1G'}]

is_all = [lis1,lis2,lis3,lis4,lis5]
#l print lis_all

new_lis = []
for j in range(2):
 lis = {}
 for i in range(len(lis_all)):
 try:
  lis = dict(lis,**lis_all[i][j])
 except Exception as e:
  pass
 # else:
 new_lis.append(lis)

print new_lis

3.結果

以上這篇Python中使用filter過濾列表的一個小技巧分享就是小編分享給大家的全部內容了，希望能給大家一個參考，也希望大家多多支援我們。