10000字Pandas基础 进阶笔记!

干货福利,第一时间送达

数据对象

pandas主要有两种数据对象:Series、DataFrame

注: 后面代码使用pandas版本0.20.1,通过import pandas as pd引入

1. Series

Series是一种带有索引的序列对象。

简单创建如下:

# 通过传入一个序列给pd.Series初始化一个Series对象, 比如lists1=pd.Series(list('1234'))print(s1)0 11 22 33 4dtype:object


2. DataFrame

类似与数据库table有行列的数据对象。

创建方式如下:

# 通过传入一个numpy的二维数组或者dict对象给pd.DataFrame初始化一个DataFrame对象# 通过numpy二维数组import numpy as npdf1 = pd.DataFrame(np.random.randn(6,4))print(df1)    0   1   2   30   -0.646340   -1.249943   0.393323    -1.5618731   0.371630    0.069426    1.693097    0.9074192   -0.328575   -0.256765   0.693798    -0.7873433   1.875764    -0.416275   -1.028718   0.1582594   1.644791    -1.321506   -0.337425   0.8206895   0.006391    -1.447894   0.506203    0.977295# 通过dict字典df2 = pd.DataFrame({ 'A' : 1.,                     'B' : pd.Timestamp('20130102'),                                                                     'C' :pd.Series(1,index=list(range(4)),dtype='float32'),                      'D' : np.array([3] * 4,dtype='int32'),                                                               'E' : pd.Categorical(['test','train','test','train']),                                          'F' : 'foo' })print(df2)    A   B   C   D   E   F0   1.0 2013-01-02  1.0 3   test    foo1   1.0 2013-01-02  1.0 3   train   foo2   1.0 2013-01-02  1.0 3   test    foo3   1.0 2013-01-02  1.0 3   train   foo

3. 索引

不管是Series对象还是DataFrame对象都有一个对对象相对应的索引,Series的索引类似于每个元素, DataFrame的索引对应着每一行。

查看:在创建对象的时候,每个对象都会初始化一个起始值为0,自增的索引列表, DataFrame同理。

# 打印对象的时候,第一列就是索引print(s1)0 11 22 33 4dtype: object

# 或者只查看索引, DataFrame同理print(s1.index)

增删查改

这里的增删查改主要基于DataFrame对象,为了有足够数据用于展示,这里选择tushare的数据。

1. tushare安装

ipinstall tushare

创建数据对象如下:

import tushare as tsdf = ts.get_k_data('000001')

DataFrame 行列,axis 图解:

2. 查询

查看每列的数据类型

# 查看df数据类型df.dtypesdate       objectopen        float64close        float64high         float64low          float64volume    float64code       objectdtype: object

查看指定指定数量的行:head函数默认查看前5行,tail函数默认查看后5行,可以传递指定的数值用于查看指定行数。

查看前5行df.head()date open close high low volume code0 2015-12-23 9.927 9.935 10.174 9.871 1039018.0 0000011 2015-12-24 9.919 9.823 9.998 9.744 640229.0 0000012 2015-12-25 9.855 9.879 9.927 9.815 399845.0 0000013 2015-12-28 9.895 9.537 9.919 9.537 822408.0 0000014 2015-12-29 9.545 9.624 9.632 9.529 619802.0 000001# 查看后5行df.tail()date open close high low volume code636 2018-08-01 9.42 9.15 9.50 9.11 814081.0 000001637 2018-08-02 9.13 8.94 9.15 8.88 931401.0 000001638 2018-08-03 8.93 8.91 9.10 8.91 476546.0 000001639 2018-08-06 8.94 8.94 9.11 8.89 554010.0 000001640 2018-08-07 8.96 9.17 9.17 8.88 690423.0 000001# 查看前10行df.head(10)date open close high low volume code0 2015-12-23 9.927 9.935 10.174 9.871 1039018.0 0000011 2015-12-24 9.919 9.823 9.998 9.744 640229.0 0000012 2015-12-25 9.855 9.879 9.927 9.815 399845.0 0000013 2015-12-28 9.895 9.537 9.919 9.537 822408.0 0000014 2015-12-29 9.545 9.624 9.632 9.529 619802.0 0000015 2015-12-30 9.624 9.632 9.640 9.513 532667.0 0000016 2015-12-31 9.632 9.545 9.656 9.537 491258.0 0000017 2016-01-04 9.553 8.995 9.577 8.940 563497.0 0000018 2016-01-05 8.972 9.075 9.210 8.876 663269.0 0000019 2016-01-06 9.091 9.179 9.202 9.067 515706.0 000001

查看某一行或多行,某一列或多列

# 查看第一行df[0:1]    date    open    close   high    low volume  code0   2015-12-23  9.927   9.935   10.174  9.871   1039018.0   000001# 查看 10到20行df[10:21]    date    open    close   high    low volume  code10  2016-01-07  9.083   8.709   9.083   8.685   174761.0    00000111  2016-01-08  8.924   8.852   8.987   8.677   747527.0    00000112  2016-01-11  8.757   8.566   8.820   8.502   732013.0    00000113  2016-01-12  8.621   8.605   8.685   8.470   561642.0    00000114  2016-01-13  8.669   8.526   8.709   8.518   391709.0    00000115  2016-01-14  8.430   8.574   8.597   8.343   666314.0    00000116  2016-01-15  8.486   8.327   8.597   8.295   448202.0    00000117  2016-01-18  8.231   8.287   8.406   8.199   421040.0    00000118  2016-01-19  8.319   8.526   8.582   8.287   501109.0    00000119  2016-01-20  8.518   8.390   8.597   8.311   603752.0    00000120  2016-01-21  8.343   8.215   8.558   8.215   606145.0    000001# 查看看Date列前5个数据df['date'].head() # 或者df.date.head()0    2015-12-231    2015-12-242    2015-12-253    2015-12-284    2015-12-29Name: date, dtype: object# 查看看Date列,code列, open列前5个数据df[['date','code', 'open']].head()    date    code    open0   2015-12-23  000001  9.9271   2015-12-24  000001  9.9192   2015-12-25  000001  9.8553   2015-12-28  000001  9.8954   2015-12-29  000001  9.545

使用行列组合条件查询

# 查看date, code列的第10行df.loc[10, ['date', 'code']]
date 2016-01-07code 000001Name: 10, dtype: object# 查看date, code列的第10行到20行df.loc[10:20, ['date', 'code']]
date code10 2016-01-07 00000111 2016-01-08 00000112 2016-01-11 00000113 2016-01-12 00000114 2016-01-13 00000115 2016-01-14 00000116 2016-01-15 00000117 2016-01-18 00000118 2016-01-19 00000119 2016-01-20 00000120 2016-01-21 000001
# 查看第一行,open列的数据df.loc[0, 'open']9.9269999999999996

通过位置查询:值得注意的是上面的索引值就是特定的位置。

# 查看第1行()df.iloc[0]date      2015-12-24open           9.919close          9.823high           9.998low            9.744volume        640229code          000001Name: 0, dtype: object# 查看最后一行df.iloc[-1]date      2018-08-08open            9.16close           9.12high            9.16low              9.1volume         29985code          000001Name: 640, dtype: object# 查看第一列,前5个数值df.iloc[:,0].head()0    2015-12-241    2015-12-252    2015-12-283    2015-12-294    2015-12-30Name: date, dtype: object# 查看前2到4行,第1,3列df.iloc[2:4,[0,2]]date    close2   2015-12-28  9.5373   2015-12-29  9.624

通过条件筛选:

查看open列大于10的前5行df[df.open > 10].head()
date open close high low volume code378 2017-07-14 10.483 10.570 10.609 10.337 1722570.0 000001379 2017-07-17 10.619 10.483 10.987 10.396 3273123.0 000001380 2017-07-18 10.425 10.716 10.803 10.299 2349431.0 000001381 2017-07-19 10.657 10.754 10.851 10.551 1933075.0 000001382 2017-07-20 10.745 10.638 10.880 10.580 1537338.0 000001
# 查看open列大于10且open列小于10.6的前五行df[(df.open > 10) & (df.open < 10.6)].head() date open close high low volume code378 2017-07-14 10.483 10.570 10.609 10.337 1722570.0 000001380 2017-07-18 10.425 10.716 10.803 10.299 2349431.0 000001387 2017-07-27 10.550 10.422 10.599 10.363 1194490.0 000001388 2017-07-28 10.441 10.569 10.638 10.412 819195.0 000001390 2017-08-01 10.471 10.865 10.904 10.432 2035709.0 000001
# 查看open列大于10或open列小于10.6的前五行df[(df.open > 10) | (df.open < 10.6)].head() date open close high low volume code0 2015-12-24 9.919 9.823 9.998 9.744 640229.0 0000011 2015-12-25 9.855 9.879 9.927 9.815 399845.0 0000012 2015-12-28 9.895 9.537 9.919 9.537 822408.0 0000013 2015-12-29 9.545 9.624 9.632 9.529 619802.0 0000014 2015-12-30 9.624 9.632 9.640 9.513 532667.0 000001

3. 增加

在前面已经简单的说明Series, DataFrame的创建,这里说一些常用有用的创建方式。

# 创建2018-08-08到2018-08-15的时间序列,默认时间间隔为Days2 = pd.date_range('20180808', periods=7)print(s2)DatetimeIndex(['2018-08-08', '2018-08-09', '2018-08-10', '2018-08-11',               '2018-08-12', '2018-08-13', '2018-08-14'],                                              dtype='datetime64[ns]', freq='D')# 指定2018-08-08 00:00 到2018-08-09 00:00 时间间隔为小时# freq参数可使用参数, 参考: http://pandas.pydata.org/pandas-docs/stable/timeseries.html#offset-aliases s3 = pd.date_range('20180808', '20180809', freq='H')print(s2)DatetimeIndex(['2018-08-08 00:00:00', '2018-08-08 01:00:00',               '2018-08-08 02:00:00', '2018-08-08 03:00:00',               '2018-08-08 04:00:00', '2018-08-08 05:00:00',               '2018-08-08 06:00:00', '2018-08-08 07:00:00',               '2018-08-08 08:00:00', '2018-08-08 09:00:00',               '2018-08-08 10:00:00', '2018-08-08 11:00:00',               '2018-08-08 12:00:00', '2018-08-08 13:00:00',               '2018-08-08 14:00:00', '2018-08-08 15:00:00',               '2018-08-08 16:00:00', '2018-08-08 17:00:00',               '2018-08-08 18:00:00', '2018-08-08 19:00:00',               '2018-08-08 20:00:00', '2018-08-08 21:00:00',               '2018-08-08 22:00:00', '2018-08-08 23:00:00',               '2018-08-09 00:00:00'],               dtype='datetime64[ns]', freq='H')# 通过已有序列创建时间序列s4 = pd.to_datetime(df.date.head())print(s4)0   2015-12-241   2015-12-252   2015-12-283   2015-12-294   2015-12-30Name: date, dtype: datetime64[ns]

4. 修改

# 将df 的索引修改为date列的数据,并且将类型转换为datetime类型df.index = pd.to_datetime(df.date)df.head()
date open close high low volume code date 2015-12-24 2015-12-24 9.919 9.823 9.998 9.744 640229.0 0000012015-12-25 2015-12-25 9.855 9.879 9.927 9.815 399845.0 0000012015-12-28 2015-12-28 9.895 9.537 9.919 9.537 822408.0 0000012015-12-29 2015-12-29 9.545 9.624 9.632 9.529 619802.0 0000012015-12-30 2015-12-30 9.624 9.632 9.640 9.513 532667.0 000001# 修改列的字段df.columns = ['Date', 'Open','Close','High','Low','Volume','Code']print(df.head())
Date Open Close High Low Volume Code date2015-12-24 2015-12-24 9.919 9.823 9.998 9.744 640229.0 0000012015-12-25 2015-12-25 9.855 9.879 9.927 9.815 399845.0 0000012015-12-28 2015-12-28 9.895 9.537 9.919 9.537 822408.0 0000012015-12-29 2015-12-29 9.545 9.624 9.632 9.529 619802.0 0000012015-12-30 2015-12-30 9.624 9.632 9.640 9.513 532667.0 000001# 将Open列每个数值加1, apply方法并不直接修改源数据,所以需要将新值复制给dfdf.Open = df.Open.apply(lambda x: x+1)df.head()
Date Open Close High Low Volume Code date2015-12-24 2015-12-24 10.919 9.823 9.998 9.744 640229.0 0000012015-12-25 2015-12-25 10.855 9.879 9.927 9.815 399845.0 0000012015-12-28 2015-12-28 10.895 9.537 9.919 9.537 822408.0 0000012015-12-29 2015-12-29 10.545 9.624 9.632 9.529 619802.0 0000012015-12-30 2015-12-30 10.624 9.632 9.640 9.513 532667.0 000001# 将Open,Close列都数值上加1,如果多列,apply接收的对象是整个列df[['Open', 'Close']].head().apply(lambda x: x.apply(lambda x: x+1))
Open Closedate 2015-12-24 11.919 10.8232015-12-25 11.855 10.8792015-12-28 11.895 10.5372015-12-29 11.545 10.6242015-12-30 11.624 10.632

5. 删除

通过drop方法drop指定的行或者列。

注意: drop方法并不直接修改源数据,如果需要使源dataframe对象被修改,需要传入inplace=True,通过之前的axis图解,知道行的值(或者说label)在axis=0,列的值(或者说label)在axis=1。

# 删除指定列,删除Open列df.drop('Open', axis=1).head() #或者df.drop(df.columns[1])    Date    Close   High      Low Volume     Code       date        2015-12-24  2015-12-24  9.823   9.998   9.744   640229.0    0000012015-12-25  2015-12-25  9.879   9.927   9.815   399845.0    0000012015-12-28  2015-12-28  9.537   9.919   9.537   822408.0    0000012015-12-29  2015-12-29  9.624   9.632   9.529   619802.0    0000012015-12-30  2015-12-30  9.632   9.640   9.513   532667.0    000001# 删除第1,3列. 即Open,High列df.drop(df.columns[[1,3]], axis=1).head() # 或df.drop(['Open', 'High], axis=1).head()        Date    Close      Low Volume       Code         date 2015-12-24  2015-12-24  9.823   9.744   640229.0    000001 2015-12-25  2015-12-25  9.879   9.815   399845.0    000001 2015-12-28  2015-12-28  9.537   9.537   822408.0    000001 2015-12-29  2015-12-29  9.624   9.529   619802.0    000001 2015-12-30  2015-12-30  9.632   9.513   532667.0    000001

pandas常用参数

数值显示格式:当数值很大的时候pandas默认会使用科学计数法

# float数据类型以{:.4f}格式显示,即显示完整数据且保留后四位pd.options.display.float_format = '{:.4f}'.format

pandas常用函数

1. 统计

# descibe方法会计算每列数据对象是数值的count, mean, std, min, max, 以及一定比率的值df.describe()     Open    Close   High    Low Volumecount   641.0000    641.0000    641.0000    641.0000    641.0000mean    10.7862 9.7927  9.8942  9.6863  833968.6162std 1.5962  1.6021  1.6620  1.5424  607731.6934min 8.6580  7.6100  7.7770  7.4990  153901.000025% 9.7080  8.7180  8.7760  8.6500  418387.000050% 10.0770 9.0960  9.1450  8.9990  627656.000075% 11.8550 10.8350 10.9920 10.7270 1039297.0000max 15.9090 14.8600 14.9980 14.4470 4262825.0000# 单独统计Open列的平均值df.Open.mean()10.786248049922001# 查看居于95%的值, 默认线性拟合df.Open.quantile(0.95)14.187# 查看Open列每个值出现的次数df.Open.value_counts().head()9.8050    129.8630    109.8440    109.8730    109.8830     8Name: Open, dtype: int64


2. 缺失值处理

删除或者填充缺失值。

# 删除含有NaN的任意行df.dropna(how='any')
# 删除含有NaN的任意列df.dropna(how='any', axis=1)
# 将NaN的值改为5df.fillna(value=5)


3. 排序

按行或者列排序, 默认也不修改源数据。

# 按列排序df.sort_index(axis=1).head()    Close   Code    Date    High    Low Open    Volumedate2015-12-24  9.8230  000001  2015-12-24  9.9980  9.7440  10.9190 640229.00002015-12-25  1.0000  000001  2015-12-25  1.0000  9.8150  10.8550 399845.00002015-12-28  1.0000  000001  2015-12-28  1.0000  9.5370  10.8950 822408.00002015-12-29  9.6240  000001  2015-12-29  9.6320  9.5290  10.5450 619802.00002015-12-30  9.6320  000001  2015-12-30  9.6400  9.5130  10.6240 532667.0000# 按行排序,不递增df.sort_index(ascending=False).head()        Date    Open    Close   High    Low Volume  Code   date2018-08-08  2018-08-08  10.1600 9.1100  9.1600  9.0900  153901.0000 0000012018-08-07  2018-08-07  9.9600  9.1700  9.1700  8.8800  690423.0000 0000012018-08-06  2018-08-06  9.9400  8.9400  9.1100  8.8900  554010.0000 0000012018-08-03  2018-08-03  9.9300  8.9100  9.1000  8.9100  476546.0000 0000012018-08-02  2018-08-02  10.1300 8.9400  9.1500  8.8800  931401.0000 000001

安装某一列的值排序

# 按照Open列的值从小到大排序df.sort_values(by='Open') Date Open Close High Low Volume Codedate 2016-03-01 2016-03-01 8.6580 7.7220 7.7770 7.6260 377910.0000 0000012016-02-15 2016-02-15 8.6900 7.7930 7.8410 7.6820 278499.0000 0000012016-01-29 2016-01-29 8.7540 7.9610 8.0240 7.7140 544435.0000 0000012016-03-02 2016-03-02 8.7620 8.0400 8.0640 7.7380 676613.0000 0000012016-02-26 2016-02-26 8.7770 7.7930 7.8250 7.6900 392154.0000 000001


4. 合并

concat, 按照行方向或者列方向合并。

# 分别取0到2行,2到4行,4到9行组成一个列表,通过concat方法按照axis=0,行方向合并, axis参数不指定,默认为0split_rows = [df.iloc[0:2,:],df.iloc[2:4,:], df.iloc[4:9]]pd.concat(split_rows)    Date    Open    Close   High    Low Volume  Codedate2015-12-24  2015-12-24  10.9190 9.8230  9.9980  9.7440  640229.0000 0000012015-12-25  2015-12-25  10.8550 1.0000  1.0000  9.8150  399845.0000 0000012015-12-28  2015-12-28  10.8950 1.0000  1.0000  9.5370  822408.0000 0000012015-12-29  2015-12-29  10.5450 9.6240  9.6320  9.5290  619802.0000 0000012015-12-30  2015-12-30  10.6240 9.6320  9.6400  9.5130  532667.0000 0000012015-12-31  2015-12-31  10.6320 9.5450  9.6560  9.5370  491258.0000 0000012016-01-04  2016-01-04  10.5530 8.9950  9.5770  8.9400  563497.0000 0000012016-01-05  2016-01-05  9.9720  9.0750  9.2100  8.8760  663269.0000 0000012016-01-06  2016-01-06  10.0910 9.1790  9.2020  9.0670  515706.0000 000001# 分别取2到3列,3到5列,5列及以后列数组成一个列表,通过concat方法按照axis=1,列方向合并split_columns = [df.iloc[:,1:2], df.iloc[:,2:4], df.iloc[:,4:]]pd.concat(split_columns, axis=1).head()    Open    Close   High    Low Volume     Code    date2015-12-24  10.9190 9.8230  9.9980  9.7440  640229.0000 0000012015-12-25  10.8550 1.0000  1.0000  9.8150  399845.0000 0000012015-12-28  10.8950 1.0000  1.0000  9.5370  822408.0000 0000012015-12-29  10.5450 9.6240  9.6320  9.5290  619802.0000 0000012015-12-30  10.6240 9.6320  9.6400  9.5130  532667.0000 000001

追加行, 相应的还有insert, 插入插入到指定位置

# 将第一行追加到最后一行df.append(df.iloc[0,:], ignore_index=True).tail()

Date Open Close High Low Volume Code637 2018-08-03 9.9300 8.9100 9.1000 8.9100 476546.0000 000001638 2018-08-06 9.9400 8.9400 9.1100 8.8900 554010.0000 000001639 2018-08-07 9.9600 9.1700 9.1700 8.8800 690423.0000 000001640 2018-08-08 10.1600 9.1100 9.1600 9.0900 153901.0000 000001641 2015-12-24 10.9190 9.8230 9.9980 9.7440 640229.0000 000001

5. 对象复制

由于dataframe是引用对象,所以需要显示调用copy方法用以复制整个dataframe对象。

绘图

pandas的绘图是使用matplotlib,如果想要画的更细致, 可以使用matplotplib,不过简单的画一些图还是不错的。

因为上图太麻烦,这里就不配图了,可以在资源文件里面查看pandas-blog.ipynb文件或者自己敲一遍代码。

# 这里使用notbook,为了直接在输出中显示,需要以下配置%matplotlib inline# 绘制Open,Low,Close.High的线性图df[['Open', 'Low', 'High', 'Close']].plot()# 绘制面积图df[['Open', 'Low', 'High', 'Close']].plot(kind='area')

数据读写

读写常见文件格式,如csv,excel,json等,甚至是读取“系统的剪切板”这个功能有时候很有用。直接将鼠标选中复制的内容读取创建dataframe对象。

# 将df数据保存到当前工作目录的stock.csv文件df.to_csv('stock.csv')
# 查看stock.csv文件前5行with open('stock.csv') as rf: print(rf.readlines()[:5])
['date,Date,Open,Close,High,Low,Volume,Code\n', '2015-12-24,2015-12-24,9.919,9.823,9.998,9.744,640229.0,000001\n', '2015-12-25,2015-12-25,9.855,9.879,9.927,9.815,399845.0,000001\n', '2015-12-28,2015-12-28,9.895,9.537,9.919,9.537,822408.0,000001\n', '2015-12-29,2015-12-29,9.545,9.624,9.632,9.529,619802.0,000001\n']
# 读取stock.csv文件并将第一行作为indexdf2 = pd.read_csv('stock.csv', index_col=0)df2.head()
Date Open Close High Low Volume Codedate 2015-12-24 2015-12-24 9.9190 9.8230 9.9980 9.7440 640229.0000 12015-12-25 2015-12-25 9.8550 9.8790 9.9270 9.8150 399845.0000 12015-12-28 2015-12-28 9.8950 9.5370 9.9190 9.5370 822408.0000 12015-12-29 2015-12-29 9.5450 9.6240 9.6320 9.5290 619802.0000 12015-12-30 2015-12-30 9.6240 9.6320 9.6400 9.5130 532667.0000 1
# 读取stock.csv文件并将第一行作为index,并且将000001作为str类型读取, 不然会被解析成整数df2 = pd.read_csv('stock.csv', index_col=0, dtype={'Code': str})df2.head()

简单实例

这里以处理web日志为例,也许不太实用,因为ELK处理这些绰绰有余,不过喜欢什么自己来也未尝不可。

1. 分析access.log

日志文件: https://raw.githubusercontent.com/Apache-Labor/labor/master/labor-04/labor-04-example-access.log

2. 日志格式及示例

# 日志格式# 字段说明, 参考:https://ru.wikipedia.org/wiki/Access.log %h%l%u%t \“%r \”%> s%b \“%{Referer} i \”\“%{User-Agent} i \”# 具体示例75.249.65.145 US - [2015-09-02 10:42:51.003372] 'GET /cms/tina-access-editor-for-download/ HTTP/1.1' 200 7113 '-' 'Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)' www.example.com 124.165.3.7 443 redirect-handler - + '-' Vea2i8CoAwcAADevXAgAAAAB TLSv1.2 ECDHE-RSA-AES128-GCM-SHA256 701 12118 -% 88871 803 0 0 0 0

3. 读取并解析日志文件

解析日志文件

HOST = r'^(?P<host>.*?)'SPACE = r'\s'IDENTITY = r'\S+'USER = r'\S+'TIME = r'\[(?P<time>.*?)\]'# REQUEST = r'\'(?P<request>.*?)\''REQUEST = r'\'(?P<method>.+?)\s(?P<path>.+?)\s(?P<http_protocol>.*?)\''STATUS = r'(?P<status>\d{3})'SIZE = r'(?P<size>\S+)'REFER = r'\S+'USER_AGENT = r'\'(?P<user_agent>.*?)\''
REGEX = HOST+SPACE+IDENTITY+SPACE+USER+SPACE+TIME+SPACE+REQUEST+SPACE+STATUS+SPACE+SIZE+SPACE+IDENTITY+USER_AGENT+SPACEline = '79.81.243.171 - - [30/Mar/2009:20:58:31 +0200] 'GET /exemples.php HTTP/1.1' 200 11481 'http://www.facades.fr/' 'Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; .NET CLR 1.0.3705; .NET CLR 1.1.4322; Media Center PC 4.0; .NET CLR 2.0.50727)' '-''reg = re.compile(REGEX)reg.match(line).groups()

将数据注入DataFrame对象

COLUMNS = ['Host', 'Time', 'Method', 'Path', 'Protocol', 'status', 'size', 'User_Agent']field_lis = []with open('access.log') as rf:    for line in rf:        # 由于一些记录不能匹配,所以需要捕获异常, 不能捕获的数据格式如下        # 80.32.156.105 - - [27/Mar/2009:13:39:51 +0100] 'GET  HTTP/1.1' 400 - '-' '-' '-'        # 由于重点不在写正则表达式这里就略过了        try:            fields = reg.match(line).groups()        except Exception as e:            #print(e)            #print(line)            pass        field_lis.append(fields)log_df  = pd.DataFrame(field_lis)# 修改列名log_df.columns = COLUMNSdef parse_time(value):    try:        return pd.to_datetime(value)    except Exception as e:        print(e)        print(value)# 将Time列的值修改成pandas可解析的时间格式log_df.Time = log_df.Time.apply(lambda x: x.replace(':', ' ', 1))log_df.Time = log_df.Time.apply(parse_time)# 修改index, 将Time列作为index,并drop掉在Time列log_df.index = pd.to_datetime(log_df.Time) log_df.drop('Time', inplace=True)log_df.head()    Host    Time    Method  Path    Protocol    status  size    User_AgentTime2009-03-22 06:00:32 88.191.254.20   2009-03-22 06:00:32 GET /   HTTP/1.0    200 8674    '-2009-03-22 06:06:20 66.249.66.231   2009-03-22 06:06:20 GET /popup.php?choix=-89    HTTP/1.1    200 1870    'Mozilla/5.0 (compatible; Googlebot/2.1; +htt...2009-03-22 06:11:20 66.249.66.231   2009-03-22 06:11:20 GET /specialiste.php    HTTP/1.1    200 10743   'Mozilla/5.0 (compatible; Googlebot/2.1; +htt...2009-03-22 06:40:06 83.198.250.175  2009-03-22 06:40:06 GET /   HTTP/1.1    200 8714    'Mozilla/4.0 (compatible; MSIE 7.0; Windows N...2009-03-22 06:40:06 83.198.250.175  2009-03-22 06:40:06 GET /style.css  HTTP/1.1    200 1692    'Mozilla/4.0 (compatible; MSIE 7.0; Windows N...

查看数据类型

# 查看数据类型log_df.dtypes
Host objectTime datetime64[ns]Method objectPath objectProtocol objectstatus objectsize objectUser_Agent objectdtype: object

由上可知, 除了Time字段是时间类型,其他都是object,但是Size, Status应该为数字

def parse_number(value):    try:        return pd.to_numeric(value)    except Exception as e:        pass        return 0# 将Size,Status字段值改为数值类型log_df[['Status','Size']] = log_df[['Status','Size']].apply(lambda x: x.apply(parse_number))log_df.dtypesHost                  objectTime          datetime64[ns]Method                objectPath                  objectProtocol              objectStatus                 int64Size                   int64User_Agent            objectdtype: object

统计status数据

# 统计不同status值的次数log_df.Status.value_counts()
200 5737304 1540404 1186 400 251302 37403 3206 2Name: Status, dtype: int64

绘制pie图

log_df.Status.value_counts().plot(kind='pie', figsize=(10,8))

查看日志文件时间跨度

log_df.index.max() - log_df.index.min()Timedelta('15 days 11:12:03')

分别查看起始,终止时间

print(log_df.index.max())print(log_df.index.min())2009-04-06 17:12:352009-03-22 06:00:32

按照此方法还可以统计Method, User_Agent字段 ,不过User_Agent还需要额外清洗以下数据。

统计top 10 IP地址

91.121.31.184 74588.191.254.20 44141.224.252.122 420194.2.62.185 25586.75.35.144 184208.89.192.106 17079.82.3.8 16190.3.72.207 15762.147.243.132 15081.249.221.143 141Name: Host, dtype: int64

绘制请求走势图

log_df2 = log_df.copy()# 为每行加一个request字段,值为1log_df2['Request'] = 1# 每一小时统计一次request数量,并将NaN值替代为0,最后绘制线性图,尺寸为16x9log_df2.Request.resample('H').sum().fillna(0).plot(kind='line',figsize=(16,10))

分别绘图

分别对202,304,404状态重新取样,并放在一个列表里面req_df_lis = [log_df2[log_df2.Status == 200].Request.resample('H').sum().fillna(0), log_df2[log_df2.Status == 304].Request.resample('H').sum().fillna(0), log_df2[log_df2.Status == 404].Request.resample('H').sum().fillna(0) ]

# 将三个dataframe组合起来req_df = pd.concat(req_df_lis,axis=1)req_df.columns = ['200', '304', '404']# 绘图req_df.plot(figsize=(16,10))

End.

作者:youerning

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