推荐学习书目
› Learn Python the Hard Way
Python Sites
› PyPI - Python Package Index
› http://diveintopython.org/toc/index.html
› Pocoo
值得关注的项目
› PyPy
› Celery
› Jinja2
› Read the Docs
› gevent
› pyenv
› virtualenv
› Stackless Python
› Beautiful Soup
› 结巴中文分词
› Green Unicorn
› Sentry
› Shovel
› Pyflakes
› pytest
Python 编程
› pep8 Checker
Styles
› PEP 8
› Google Python Style Guide
› Code Style from The Hitchhiker's Guide
wsds
V2EX  ›  Python

Python 菜鸡请教

  •  1
     
  •   wsds · Jun 15, 2018 · 6380 views
    This topic created in 3066 days ago, the information mentioned may be changed or developed.

    有这么一堆数据:

    #test.log
    a, 1.324171
    b, 0.000126
    c, 1.970941
    a, 1.469649
    b, 0.000124
    c, 0.512929
    a, 1.290920
    b, 0.000118
    c, 0.259524
    a, 0.495958
    b, 0.000123
    c, 0.910949
    a, 1.268038
    b, 0.000118
    c, 1.016419
    a, 1.856081
    b, 0.000120
    c, 1.400075
    a, 1.314131
    b, 0.000140
    

    想要用 python 把左边的 key 一样的合并,但 value 要取它所有的和,还有平均值

    搞了半天,发现搞不定,也是尴尬,以下还是个半成品,搞不下去了,报错,求大神指点一些简单方法

    def two(file):
    
    	arr = []
    	with open(file, "r", encoding="utf-8") as f:
    		for i in f.readlines():
    			a = i.replace("\n", '').strip()
    			if a.split(",")[0] not in arr:
    				arr.append(a.split(",")[0])
    	ser = -1
    	while True:
    		ser += 1
    		try:
    			if a.split(",")[ser] == arr[ser]:
    				print(a.split(",")[ser])
    		except IndexError:
    			print("end!")
    			break
    
    
    two("test.log")
    
    
    47 replies  •  2020-09-06 22:09:24 +08:00
    linxzh1989
    linxzh1989
    Jun 15, 2018
    1
    pandas groupby sum?
    aborigine
    aborigine
    Jun 15, 2018 via iPhone
    2
    了解一下 pandas ?导入生成个 dataframe 就行了
    wsds
    wsds
    OP
    Jun 15, 2018
    3
    @aborigine 要用纯 python 处理,该怎么弄?
    wsds
    wsds
    OP
    Jun 15, 2018
    4
    @aborigine 我的意思是,不要用这种一步到位的库
    deepreader
    deepreader
    Jun 15, 2018
    5
    Dictionary 会用么?
    wsds
    wsds
    OP
    Jun 15, 2018
    6
    @deepreader 抱歉,字典我知道,但以我的水平真心实现不了
    mentalkiller
    mentalkiller
    Jun 15, 2018
    7
    @wsds #6 dict 是 python 内置的数据结构啊,不需要你自己实现
    wsds
    wsds
    OP
    Jun 15, 2018
    8
    @mentalkiller 我的意思不是实现字典的功能,我的意思是用字典,我实现不了我的需求
    lixm
    lixm
    Jun 15, 2018❤️1
    10
    ybping
    ybping
    Jun 15, 2018 via iPhone
    11
    dict 了解一下
    scriptB0y
    scriptB0y
    Jun 15, 2018❤️1
    12
    In [18]: data = """
    ...: a, 1.324171
    ...: b, 0.000126
    ...: c, 1.970941
    ...: a, 1.469649
    ...: b, 0.000124
    ...: c, 0.512929
    ...: a, 1.290920
    ...: b, 0.000118
    ...: c, 0.259524
    ...: a, 0.495958
    ...: b, 0.000123
    ...: c, 0.910949
    ...: a, 1.268038
    ...: b, 0.000118
    ...: c, 1.016419
    ...: a, 1.856081
    ...: b, 0.000120
    ...: c, 1.400075
    ...: a, 1.314131
    ...: b, 0.000140
    ...: """

    In [19]: result = {}
    ...: for line in data.splitlines():
    ...: if not line: continue
    ...: key, value = line.split(",")
    ...: result.setdefault(key, []).append(float(value))
    ...:

    In [20]: for key, values in result.items():
    ...: print(f"{key}: avg: {sum(values) / len(values)}, sum: {sum(values)}")
    ...:
    a: avg: 1.2884211428571428, sum: 9.018948
    b: avg: 0.00012414285714285714, sum: 0.000869
    c: avg: 1.0118061666666667, sum: 6.070837

    https://gist.github.com/laixintao/f4a186cea6c28fcf3dc696100458c410
    wsds
    wsds
    OP
    Jun 15, 2018
    13
    @hahastudio
    @lixm
    @scriptB0y
    非常感谢各位!学习了
    wplct
    wplct
    Jun 15, 2018
    14
    def two(file):
    data = {}
    with open(file, "r") as f:
    while True:
    s = f.readline()
    if s is None or not s:
    break
    print(s.split(', '))
    k, v = s.split(', ')
    v = float(v)
    if k not in data:
    data[k] = {
    'num': 1,
    'sum': v,
    'avg': v
    }
    else:
    data[k]['num'] += 1
    data[k]['sum'] += v
    data[k]['avg'] = data[k]['sum'] / data[k]['num']
    print(data)
    two('test.txt')
    wsds
    wsds
    OP
    Jun 15, 2018
    15
    @wplct 感谢
    araraloren
    araraloren
    Jun 15, 2018❤️3
    16
    一行脚本拯救你

    perl -nE 'state %z; my @z = split(", "); $z{@z[0]} += @z[1]; END { say for %z; } ' < test.log
    a
    9.018948
    b
    0.000869
    c
    6.070837

    perl6 -ne 'state %z; given .split(", ") { %z{.[0]} += .[1].Rat; }; END { say %z; }' < test.log
    {a => 9.018948, b => 0.000869, c => 6.070837}
    bufpay
    bufpay
    Jun 15, 2018
    17
    其实一个 for 循环就可以了
    E1n
    E1n
    Jun 15, 2018 via Android
    18
    @araraloren perl 好用,用 awk 能实现吗。。
    araraloren
    araraloren
    Jun 15, 2018
    19
    @E1n awk 肯定能实现,不过我只懂基本的 awk 脚本
    imagechans
    imagechans
    Jun 15, 2018
    20
    def stand(file):
    datas = [str(line).replace("\n","").strip().split(',')[1] for line in open(file)]
    s = sum([float(d) for d in datas])
    m = s / len(datas)
    print(s,m)


    stand("test.log")
    imagechans
    imagechans
    Jun 15, 2018
    21
    @imagechans 这是按照我自己的习惯写的
    billgreen1
    billgreen1
    Jun 15, 2018❤️1
    22
    < test.log | awk -F"," '{total[$1]+=$2; occurence[$1]+=1}END{for (key in total) printf("%s\t %s \t %s\n", key, total[key], total[key]/occurence[key])}'
    slimbloody
    slimbloody
    Jun 15, 2018
    23
    default_dict
    arthasgxy
    arthasgxy
    Jun 15, 2018
    24
    @lixm
    http://chuantu.biz/t6/328/1529036276x-1404792211.jpg

    求助,不知道为什么我这里运行会这样
    arthasgxy
    arthasgxy
    Jun 15, 2018
    25
    https://gist.github.com/arthasgxy/9d1f8aae0c1e90dde5ec5e44032be4f5

    字典用的少,感觉只能写出来这种又蠢又长的
    wsds
    wsds
    OP
    Jun 15, 2018
    26
    @bufpay 发现越是看上去简单的功能,实现起来越是困难
    xpresslink
    xpresslink
    Jun 15, 2018
    27
    >>> data = """a, 1.324171
    b, 0.000126
    c, 1.970941
    a, 1.469649
    b, 0.000124
    c, 0.512929
    a, 1.290920
    b, 0.000118
    c, 0.259524
    a, 0.495958
    b, 0.000123
    c, 0.910949
    a, 1.268038
    b, 0.000118
    c, 1.016419
    a, 1.856081
    b, 0.000120
    c, 1.400075
    a, 1.314131
    b, 0.000140"""
    >>> import csv
    >>> from itertools import groupby
    >>> from operator import itemgetter as ig
    >>> {k:sum(map(lambda x:float(ig(1)(x)), v)) for k, v in groupby(sorted(csv.reader(iter(data.splitlines())), key=ig(0)), key=ig(0))}
    {'a': 9.018948, 'b': 0.000869, 'c': 6.070837}
    >>>
    Xiaobaixiao
    Xiaobaixiao
    Jun 15, 2018
    28
    from collections import defaultdict

    logData='''a, 1.324171
    b, 0.000126
    c, 1.970941
    a, 1.469649
    b, 0.000124
    c, 0.512929
    a, 1.290920
    b, 0.000118
    c, 0.259524
    a, 0.495958
    b, 0.000123
    c, 0.910949
    a, 1.268038
    b, 0.000118
    c, 1.016419
    a, 1.856081
    b, 0.000120
    c, 1.400075
    a, 1.314131
    b, 0.000140'''

    def solve(logData):
    logList=[]
    logDict=defaultdict(int)
    for line in logData.splitlines():
    newList = line.split(',')
    k=newList[0]
    v=float(newList[1])
    logList.append(k)
    logDict[k]+=v
    for k,v in logDict.items():
    avg = v/logList.count(k)
    print("{0} 总和:{1} , 平均值:{2}".format(k,v,avg))


    >>> solve(logData)
    a 总和:9.018948 , 平均值:1.2884211428571428
    b 总和:0.000869 , 平均值:0.00012414285714285714
    c 总和:6.070837 , 平均值:1.0118061666666667
    zhang0320
    zhang0320
    Jun 15, 2018
    29
    with open('data.txt', 'r') as f:
    data = f.read()
    dict_data = {}
    for i in data.split('\n'):
    if i.split(',')[0] not in dict_data:
    dict_data[i.split(',')[0]]=float(i.split(',')[1])
    dict_data[i.split(',')[0]]=dict_data[i.split(',')[0]]+float(i.split(',')[1])

    print(dict_data)



    我是个新手菜鸟,不知道这种想法对不对。。。
    zhang0320
    zhang0320
    Jun 15, 2018
    30
    with open('data.txt', 'r') as f:
    data = f.read()
    dict_data = {}
    for i in data.split('\n'):
    if i.split(',')[0] not in dict_data:
    dict_data[i.split(',')[0]] = float(i.split(',')[1])
    else:
    dict_data[i.split(',')[0]] = dict_data[i.split(',')[0]] + float(i.split(',')[1])

    print(dict_data)


    不好意思 忘了个 else:
    Alexhex
    Alexhex
    Jun 15, 2018
    31
    拷到 Excel 里一个数据透视表搞定美滋滋。
    ful1v1dcker
    ful1v1dcker
    Jun 15, 2018
    32
    什么鬼,V 站 markdown 失效了?全是代码坨啊。。。
    reself
    reself
    Jun 15, 2018 via Android
    33
    @araraloren 哈哈 perl 自带代码混淆
    araraloren
    araraloren
    Jun 15, 2018
    34
    @ful1v1dcker 本来就是这样,只支持楼主的。。不然还需要什么 chrome markdown 插件(外面那个帖子)
    JCZ2MkKb5S8ZX9pq
    JCZ2MkKb5S8ZX9pq
    Jun 15, 2018
    35
    d = {}
    逐行
    k, v = (i.strip() for i in text.split(','))
    d.setdefault(k, []) # 建个列表
    d[k].append(float(v))

    这样直观一点,然后求值啥的慢慢折腾呗。
    lixm
    lixm
    Jun 15, 2018
    36
    @arthasgxy 因为是 yield, 所以是一个生成器
    gnozix
    gnozix
    Jun 15, 2018
    37
    我意思一下:
    ```python
    temp = {}
    for i, j in dict or tuple:
    if i in temp:
    temp[i] = float(j)
    else:
    temp[i] += float(j)
    ```
    ful1v1dcker
    ful1v1dcker
    Jun 15, 2018
    38
    @araraloren 噢好吧,果然没用最垃圾只有更垃圾
    nebu1a
    nebu1a
    Jun 15, 2018
    39
    def pivot_table():
    with open('data.txt', 'r') as f:
    all_data = f.readlines()[1:]
    keys = []
    result = {}
    count = {}

    for data in all_data:
    content = data.split(',')
    key = content[0]
    value = float(content[1].strip())

    # 添加键
    if key not in keys:
    keys.append(key)
    result[key] = value
    count[key] = 1
    else:
    result[key] += value
    count[key] += 1

    print('元素:', keys)
    print('元素个数:', count)
    print('和:', result)

    print('\n 统计信息(元素,和,平均值):')
    for k, v in result.items():
    avg = v / count[k]
    print(k, v, avg)


    ----------输出-----------
    元素: ['a', 'b', 'c']
    元素个数: {'a': 7, 'b': 7, 'c': 6}
    和: {'a': 9.018948, 'b': 0.000869, 'c': 6.070837}

    统计信息(元素,和,平均值):
    a 9.018948 1.2884211428571428
    b 0.000869 0.00012414285714285714
    c 6.070837 1.0118061666666667
    gpj22pYlv2qYiZ8U
    gpj22pYlv2qYiZ8U
    Jun 15, 2018
    40
    def two(file):

    num_dict = {}
    with open(file, "r", encoding="utf-8") as f:
    for i in f.readlines():
    a = i.replace("\n", '').strip()
    line_list = a.split(",")
    if line_list[0] not in num_dict:
    num_dict[line_list[0]] = [line_list[1], 1]
    else:
    num_dict[line_list[0]] = [float(num_dict[line_list[0]][0]) + float(line_list[1]), int(num_dict[line_list[0]][1]) + 1]
    for x in num_dict:
    num_dict[x].append(num_dict[x][0] / num_dict[x][1])
    print(num_dict)


    two("/Users/yourname/program/test/test.log")
    UnluckyNinja
    UnluckyNinja
    Jun 15, 2018
    41
    def text = '''a, 1.324171
    b, 0.000126
    c, 1.970941
    a, 1.469649
    b, 0.000124
    c, 0.512929
    a, 1.290920
    b, 0.000118
    c, 0.259524
    a, 0.495958
    b, 0.000123
    c, 0.910949
    a, 1.268038
    b, 0.000118
    c, 1.016419
    a, 1.856081
    b, 0.000120
    c, 1.400075
    a, 1.314131
    b, 0.000140
    '''

    // file.readLines().collect{
    text.readLines().collect{
    it.split(',')*.trim()
    }.groupBy{
    it[0]
    }.collectEntries{k, vList ->
    [(k): [sum: def sum = vList.sum{ it[1] as BigDecimal }, average: sum / vList.size()]]
    }

    /* result: [a:[sum:9.018948, average:1.2884211429], b:[sum:0.000869, average:0.0001241429], c:[sum:6.070837, average:1.0118061667]]

    groovy 写的,groovy 有的 python 肯定有,语法方法名啥的改一下应该就差不多了 */
    Binb
    Binb
    Jun 16, 2018
    42
    #!/usr/bin/env python
    # -*- coding: utf-8 -*-

    a = {}
    with open('test.log','r') as f:
    for i in f:
    j = i.split(',')
    a.setdefault(j[0],[]).append(float(j[1]))

    result = {}
    for k,v in a.items():
    s = sum(v)
    result.setdefault(k,[]).append(s)
    result[k].append(s/len(v))

    print result
    # {'a': [9.018948, 1.2884211428571428], 'c': [6.070837, 1.0118061666666667], 'b': [0.000869, 0.00012414285714285714]}
    NICCEEEE
    NICCEEEE
    Jun 16, 2018
    43
    import collections

    d = """a, 1.324171
    b, 0.000126
    c, 1.970941
    a, 1.469649
    b, 0.000124
    c, 0.512929
    a, 1.290920
    b, 0.000118
    c, 0.259524
    a, 0.495958
    b, 0.000123
    c, 0.910949
    a, 1.268038
    b, 0.000118
    c, 1.016419
    a, 1.856081
    b, 0.000120
    c, 1.400075
    a, 1.314131
    b, 0.000140"""

    L = [(i[0], i[3:]) for i in d.split('\n')]
    data_dict = collections.defaultdict(int)

    for i, j in L:
    data_dict[i] += float(j)

    print(data_dict)
    yangxiaoyong
    yangxiaoyong
    Jun 16, 2018 via Android
    44
    讲下原理的东西,map reduce 可以了解一下,首先把数据分组归类
    map (lambda x: { value: x.key, key: x.key, count: 1})
    按上面的把数据按 key 分组放好
    然后执行归约函数,将数据集合归约为一个最终结果
    reduce(lambda acc, curr: merge(acc,curr), mapdata )

    merge 根据 key 将相同 key 的数值相加得到总合,count 相加得到次数,总和除以次数可以得平均值

    最后的结果应该是 {a: { value,count,avg}}

    手机码字,凑合看吧
    bugcoder
    bugcoder
    Jun 17, 2018
    45
    没人贴 pandas 的,我就献个丑吧:
    ···
    import pandas as pd

    data_file = 'data.txt'
    data_df = pd.read_csv(data_file, comment='#', names=['key', 'value'])

    sums = data_df.groupby('key').sum()
    means = data_df.groupby('key').mean()
    ···
    mingyun
    mingyun
    Jul 15, 2018
    46
    @bugcoder 这个简单
    biglazycat
    biglazycat
    Sep 6, 2020
    47
    convert_list = {}
    for line in open('test.log'):
    k, v = line.split(',')
    convert_list.setdefault(k,[]).append(float(v.strip()))

    # print(convert_list)
    for k, v in convert_list.items():
    total_sum = sum(v)
    avg = total_sum / len(v)
    print(total_sum)
    print(avg)
    About   ·   Help   ·   Advertise   ·   Blog   ·   API   ·   FAQ   ·   Privacy   ·   Solana   ·   1942 Online   Highest 6679   ·     Select Language
    创意工作者们的社区
    World is powered by solitude
    VERSION: 3.9.8.5 · 89ms · UTC 01:10 · PVG 09:10 · LAX 17:10 · JFK 20:10
    ♥ Do have faith in what you're doing.