pandas從入門到上樓

數據對象

pandas主要有兩種數據對象php

  1. Series
  2. DataFrame

    注: 後面代碼使用pandas版本0.20.1,經過import pandas as pd引入css

Series

Series是一種帶有索引的序列對象html

建立方式

簡單建立以下git

# 經過傳入一個序列給pd.Series初始化一個Series對象, 好比list
s1 = pd.Series(list("1234"))
print(s1)
0    1
1    2
2    3
3    4
dtype: object

DataFrame

相似與數據庫table有行列的數據對象github

建立方式以下

# 經過傳入一個numpy的二維數組或者dict對象給pd.DataFrame初始化一個DataFrame對象

# 經過numpy二維數組
import numpy as np
df1 = pd.DataFrame(np.random.randn(6,4))
print(df1)
    0   1   2   3
0   -0.646340   -1.249943   0.393323    -1.561873
1   0.371630    0.069426    1.693097    0.907419
2   -0.328575   -0.256765   0.693798    -0.787343
3   1.875764    -0.416275   -1.028718   0.158259
4   1.644791    -1.321506   -0.337425   0.820689
5   0.006391    -1.447894   0.506203    0.977295

# 經過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   F
0   1.0 2013-01-02  1.0 3   test    foo
1   1.0 2013-01-02  1.0 3   train   foo
2   1.0 2013-01-02  1.0 3   test    foo
3   1.0 2013-01-02  1.0 3   train   foo

索引

不論是Series對象仍是DataFrame對象都有一個對對象相對應的索引, Series的索引相似於每一個元素, DataFrame的索引對應着每一行web

查看

在建立對象的時候,每一個對象都會初始化一個起始值爲0,自增的索引列表, DataFrame同理正則表達式

# 打印對象的時候,第一列就是索引
print(s1)
0    1
1    2
2    3
3    4
dtype: object

# 或者只查看索引, DataFrame同理
print(s1.index)

增刪查改

這裏的增刪查改主要基於DataFrame對象數據庫

爲了有足夠數據用於展現,這裏選擇tushare的數據json

tushare安裝數組

pip install tushare

建立數據對象以下

import tushare as ts
df = ts.get_k_data("000001")

DataFrame 行列,axis 圖解

pandas從入門到上樓

pandas從入門到上樓

查詢

查看每列的數據類型

# 查看df數據類型
df.dtypes
date       object
open      float64
close     float64
high      float64
low       float64
volume    float64
code       object
dtype: object

查看指定指定數量的行

head函數默認查看前5行,tail函數默認查看後5行,能夠傳遞指定的數值用於查看指定行數

查看前5行
df.head()
date    open    close   high    low volume  code
0   2015-12-23  9.927   9.935   10.174  9.871   1039018.0   000001
1   2015-12-24  9.919   9.823   9.998   9.744   640229.0    000001
2   2015-12-25  9.855   9.879   9.927   9.815   399845.0    000001
3   2015-12-28  9.895   9.537   9.919   9.537   822408.0    000001
4   2015-12-29  9.545   9.624   9.632   9.529   619802.0    000001
# 查看後5行
df.tail()
date    open    close   high    low volume  code
636 2018-08-01  9.42    9.15    9.50    9.11    814081.0    000001
637 2018-08-02  9.13    8.94    9.15    8.88    931401.0    000001
638 2018-08-03  8.93    8.91    9.10    8.91    476546.0    000001
639 2018-08-06  8.94    8.94    9.11    8.89    554010.0    000001
640 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  code
0   2015-12-23  9.927   9.935   10.174  9.871   1039018.0   000001
1   2015-12-24  9.919   9.823   9.998   9.744   640229.0    000001
2   2015-12-25  9.855   9.879   9.927   9.815   399845.0    000001
3   2015-12-28  9.895   9.537   9.919   9.537   822408.0    000001
4   2015-12-29  9.545   9.624   9.632   9.529   619802.0    000001
5   2015-12-30  9.624   9.632   9.640   9.513   532667.0    000001
6   2015-12-31  9.632   9.545   9.656   9.537   491258.0    000001
7   2016-01-04  9.553   8.995   9.577   8.940   563497.0    000001
8   2016-01-05  8.972   9.075   9.210   8.876   663269.0    000001
9   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  code
0   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  code
10  2016-01-07  9.083   8.709   9.083   8.685   174761.0    000001
11  2016-01-08  8.924   8.852   8.987   8.677   747527.0    000001
12  2016-01-11  8.757   8.566   8.820   8.502   732013.0    000001
13  2016-01-12  8.621   8.605   8.685   8.470   561642.0    000001
14  2016-01-13  8.669   8.526   8.709   8.518   391709.0    000001
15  2016-01-14  8.430   8.574   8.597   8.343   666314.0    000001
16  2016-01-15  8.486   8.327   8.597   8.295   448202.0    000001
17  2016-01-18  8.231   8.287   8.406   8.199   421040.0    000001
18  2016-01-19  8.319   8.526   8.582   8.287   501109.0    000001
19  2016-01-20  8.518   8.390   8.597   8.311   603752.0    000001
20  2016-01-21  8.343   8.215   8.558   8.215   606145.0    000001

# 查看看Date列前5個數據
df["date"].head() # 或者df.date.head()
0    2015-12-23
1    2015-12-24
2    2015-12-25
3    2015-12-28
4    2015-12-29
Name: date, dtype: object

# 查看看Date列,code列, open列前5個數據
df[["date","code", "open"]].head()
    date    code    open
0   2015-12-23  000001  9.927
1   2015-12-24  000001  9.919
2   2015-12-25  000001  9.855
3   2015-12-28  000001  9.895
4   2015-12-29  000001  9.545

使用行列組合條件查詢

# 查看date, code列的第10行
df.loc[10, ["date", "code"]]

date    2016-01-07
code        000001
Name: 10, dtype: object

# 查看date, code列的第10行到20行
df.loc[10:20, ["date", "code"]]

    date    code
10  2016-01-07  000001
11  2016-01-08  000001
12  2016-01-11  000001
13  2016-01-12  000001
14  2016-01-13  000001
15  2016-01-14  000001
16  2016-01-15  000001
17  2016-01-18  000001
18  2016-01-19  000001
19  2016-01-20  000001
20  2016-01-21  000001

# 查看第一行,open列的數據
df.loc[0, "open"]
9.9269999999999996

經過==位置==查詢

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      2015-12-24
open           9.919
close          9.823
high           9.998
low            9.744
volume        640229
code          000001
Name: 0, dtype: object

# 查看最後一行
df.iloc[-1]
date      2018-08-08
open            9.16
close           9.12
high            9.16
low              9.1
volume         29985
code          000001
Name: 640, dtype: object

# 查看第一列,前5個數值
df.iloc[:,0].head()
0    2015-12-24
1    2015-12-25
2    2015-12-28
3    2015-12-29
4    2015-12-30
Name: date, dtype: object

# 查看前2到4行,第1,3列
df.iloc[2:4,[0,2]]

date    close
2   2015-12-28  9.537
3   2015-12-29  9.624

經過條件篩選

查看open列大於10的前5行
df[df.open > 10].head()

    date    open    close   high    low volume  code
378 2017-07-14  10.483  10.570  10.609  10.337  1722570.0   000001
379 2017-07-17  10.619  10.483  10.987  10.396  3273123.0   000001
380 2017-07-18  10.425  10.716  10.803  10.299  2349431.0   000001
381 2017-07-19  10.657  10.754  10.851  10.551  1933075.0   000001
382 2017-07-20  10.745  10.638  10.880  10.580  1537338.0   000001

# 查看open列大於10且open列小於10.6的前五行
df[(df.open > 10) & (df.open < 10.6)].head()

    date    open    close   high    low volume  code
378 2017-07-14  10.483  10.570  10.609  10.337  1722570.0   000001
380 2017-07-18  10.425  10.716  10.803  10.299  2349431.0   000001
387 2017-07-27  10.550  10.422  10.599  10.363  1194490.0   000001
388 2017-07-28  10.441  10.569  10.638  10.412  819195.0    000001
390 2017-08-01  10.471  10.865  10.904  10.432  2035709.0   000001

# 查看open列大於10或open列小於10.6的前五行
df[(df.open > 10) | (df.open < 10.6)].head()

    date    open    close   high    low volume  code
0   2015-12-24  9.919   9.823   9.998   9.744   640229.0    000001
1   2015-12-25  9.855   9.879   9.927   9.815   399845.0    000001
2   2015-12-28  9.895   9.537   9.919   9.537   822408.0    000001
3   2015-12-29  9.545   9.624   9.632   9.529   619802.0    000001
4   2015-12-30  9.624   9.632   9.640   9.513   532667.0    000001

增長

在前面已經簡單的說明Series, DataFrame的建立,這裏說一些經常使用有用的建立方式

# 建立2018-08-08到2018-08-15的時間序列,默認時間間隔爲Day
s2 = 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 時間間隔爲小時
# freq參數可以使用參數, 參考: 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')

# 經過已有序列建立時間序列
s4 = pd.to_datetime(df.date.head())
print(s4)

0   2015-12-24
1   2015-12-25
2   2015-12-28
3   2015-12-29
4   2015-12-30
Name: date, dtype: datetime64[ns]

修改

# 將df 的索引修改成date列的數據,而且將類型轉換爲datetime類型
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    000001
2015-12-25  2015-12-25  9.855   9.879   9.927   9.815   399845.0    000001
2015-12-28  2015-12-28  9.895   9.537   9.919   9.537   822408.0    000001
2015-12-29  2015-12-29  9.545   9.624   9.632   9.529   619802.0    000001
2015-12-30  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
date                                                                
2015-12-24  2015-12-24  9.919  9.823  9.998  9.744  640229.0  000001
2015-12-25  2015-12-25  9.855  9.879  9.927  9.815  399845.0  000001
2015-12-28  2015-12-28  9.895  9.537  9.919  9.537  822408.0  000001
2015-12-29  2015-12-29  9.545  9.624  9.632  9.529  619802.0  000001
2015-12-30  2015-12-30  9.624  9.632  9.640  9.513  532667.0  000001

# 將Open列每一個數值加1, apply方法並不直接修改源數據,因此須要將新值複製給df
df.Open = df.Open.apply(lambda x: x+1)
df.head()

    Date    Open    Close   High    Low Volume  Code
date                            
2015-12-24  2015-12-24  10.919  9.823   9.998   9.744   640229.0    000001
2015-12-25  2015-12-25  10.855  9.879   9.927   9.815   399845.0    000001
2015-12-28  2015-12-28  10.895  9.537   9.919   9.537   822408.0    000001
2015-12-29  2015-12-29  10.545  9.624   9.632   9.529   619802.0    000001
2015-12-30  2015-12-30  10.624  9.632   9.640   9.513   532667.0    000001

# 將Open,Close列都數值上加1,若是多列,apply接收的對象是整個列
df[["Open", "Close"]].head().apply(lambda x: x.apply(lambda x: x+1))

            Open    Close
date        
2015-12-24  11.919  10.823
2015-12-25  11.855  10.879
2015-12-28  11.895  10.537
2015-12-29  11.545  10.624
2015-12-30  11.624  10.632

刪除

經過drop方法drop指定的行或者列

注意: drop方法並不直接修改源數據,若是須要使源dataframe對象被修改,須要傳入inplace=True

經過以前的axis圖解,知道行的值(或者說label)在axis=0,列的值(或者說label)在axis=1

# 刪除指定列,刪除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    000001
2015-12-25  2015-12-25  9.879   9.927   9.815   399845.0    000001
2015-12-28  2015-12-28  9.537   9.919   9.537   822408.0    000001
2015-12-29  2015-12-29  9.624   9.632   9.529   619802.0    000001
2015-12-30  2015-12-30  9.632   9.640   9.513   532667.0    000001

# 刪除第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經常使用參數

數值顯示格式

當數值很大的時候pandas默認會使用科學計數法

# float數據類型以{:.4f}格式顯示,即顯示完整數據且保留後四位
pd.options.display.float_format = '{:.4f}'.format

經常使用函數

統計

# descibe方法會計算每列數據對象是數值的count, mean, std, min, max, 以及必定比率的值
df.describe()

        Open    Close   High    Low Volume
count   641.0000    641.0000    641.0000    641.0000    641.0000
mean    10.7862 9.7927  9.8942  9.6863  833968.6162
std 1.5962  1.6021  1.6620  1.5424  607731.6934
min 8.6580  7.6100  7.7770  7.4990  153901.0000
25% 9.7080  8.7180  8.7760  8.6500  418387.0000
50% 10.0770 9.0960  9.1450  8.9990  627656.0000
75% 11.8550 10.8350 10.9920 10.7270 1039297.0000
max 15.9090 14.8600 14.9980 14.4470 4262825.0000

# 單獨統計Open列的平均值
df.Open.mean()
10.786248049922001

# 查看居於95%的值, 默認線性擬合
df.Open.quantile(0.95)
14.187

# 查看Open列每一個值出現的次數
df.Open.value_counts().head()

9.8050    12
9.8630    10
9.8440    10
9.8730    10
9.8830     8
Name: Open, dtype: int64

缺失值處理

刪除或者填充缺失值

# 刪除含有NaN的任意行
df.dropna(how='any')

# 刪除含有NaN的任意列
df.dropna(how='any', axis=1)

# 將NaN的值改成5
df.fillna(value=5)

排序

按行或者列排序, 默認也不修改源數據

# 按列排序
df.sort_index(axis=1).head()

    Close   Code    Date    High    Low Open    Volume
date                            
2015-12-24  9.8230  000001  2015-12-24  9.9980  9.7440  10.9190 640229.0000
2015-12-25  1.0000  000001  2015-12-25  1.0000  9.8150  10.8550 399845.0000
2015-12-28  1.0000  000001  2015-12-28  1.0000  9.5370  10.8950 822408.0000
2015-12-29  9.6240  000001  2015-12-29  9.6320  9.5290  10.5450 619802.0000
2015-12-30  9.6320  000001  2015-12-30  9.6400  9.5130  10.6240 532667.0000

# 按行排序,不遞增
df.sort_index(ascending=False).head()

        Date    Open    Close   High    Low Volume  Code
date                            
2018-08-08  2018-08-08  10.1600 9.1100  9.1600  9.0900  153901.0000 000001
2018-08-07  2018-08-07  9.9600  9.1700  9.1700  8.8800  690423.0000 000001
2018-08-06  2018-08-06  9.9400  8.9400  9.1100  8.8900  554010.0000 000001
2018-08-03  2018-08-03  9.9300  8.9100  9.1000  8.9100  476546.0000 000001
2018-08-02  2018-08-02  10.1300 8.9400  9.1500  8.8800  931401.0000 000001

安裝某一列的值排序

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

合併

concat, 按照行方向或者列方向合併

# 分別取0到2行,2到4行,4到9行組成一個列表,經過concat方法按照axis=0,行方向合併, axis參數不指定,默認爲0
split_rows = [df.iloc[0:2,:],df.iloc[2:4,:], df.iloc[4:9]]
pd.concat(split_rows)

    Date    Open    Close   High    Low Volume  Code
date                            
2015-12-24  2015-12-24  10.9190 9.8230  9.9980  9.7440  640229.0000 000001
2015-12-25  2015-12-25  10.8550 1.0000  1.0000  9.8150  399845.0000 000001
2015-12-28  2015-12-28  10.8950 1.0000  1.0000  9.5370  822408.0000 000001
2015-12-29  2015-12-29  10.5450 9.6240  9.6320  9.5290  619802.0000 000001
2015-12-30  2015-12-30  10.6240 9.6320  9.6400  9.5130  532667.0000 000001
2015-12-31  2015-12-31  10.6320 9.5450  9.6560  9.5370  491258.0000 000001
2016-01-04  2016-01-04  10.5530 8.9950  9.5770  8.9400  563497.0000 000001
2016-01-05  2016-01-05  9.9720  9.0750  9.2100  8.8760  663269.0000 000001
2016-01-06  2016-01-06  10.0910 9.1790  9.2020  9.0670  515706.0000 000001

# 分別取2到3列,3到5列,5列及之後列數組成一個列表,經過concat方法按照axis=1,列方向合併
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
date                        
2015-12-24  10.9190 9.8230  9.9980  9.7440  640229.0000 000001
2015-12-25  10.8550 1.0000  1.0000  9.8150  399845.0000 000001
2015-12-28  10.8950 1.0000  1.0000  9.5370  822408.0000 000001
2015-12-29  10.5450 9.6240  9.6320  9.5290  619802.0000 000001
2015-12-30  10.6240 9.6320  9.6400  9.5130  532667.0000 000001

追加行, 相應的還有insert, 插入插入到指定位置

# 將第一行追加到最後一行
df.append(df.iloc[0,:], ignore_index=True).tail()

Date    Open    Close   High    Low Volume  Code
637 2018-08-03  9.9300  8.9100  9.1000  8.9100  476546.0000 000001
638 2018-08-06  9.9400  8.9400  9.1100  8.8900  554010.0000 000001
639 2018-08-07  9.9600  9.1700  9.1700  8.8800  690423.0000 000001
640 2018-08-08  10.1600 9.1100  9.1600  9.0900  153901.0000 000001
641 2015-12-24  10.9190 9.8230  9.9980  9.7440  640229.0000 000001

對象複製

因爲dataframe是引用對象,因此須要顯示調用copy方法用以複製整個dataframe對象

繪圖

pandas的繪圖是使用matplotlib,若是想要畫的更細緻, 可使用matplotplib,不過簡單的畫一些圖仍是不錯的

由於上圖太麻煩,這裏就不配圖了,能夠在資源文件裏面查看pandas-blog.ipynb文件或者本身敲一遍代碼。

# 這裏使用notbook,爲了直接在輸出中顯示,須要如下配置
%matplotlib inline
# 繪製Open,Low,Close.High的線性圖
df[["Open", "Low", "High", "Close"]].plot()

# 繪製面積圖
df[["Open", "Low", "High", "Close"]].plot(kind="area")

數據讀寫

讀寫常見文件格式,如csv,excel,json等, 甚至是讀取==系統的剪切板==.這個功能有時候頗有用。直接將鼠標選中複製的內容讀取建立dataframe對象。

# 將df數據保存到當前工做目錄的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']

# 讀取stock.csv文件並將第一行做爲index
df2 = pd.read_csv("stock.csv", index_col=0)
df2.head()

    Date    Open    Close   High    Low Volume  Code
date                            
2015-12-24  2015-12-24  9.9190  9.8230  9.9980  9.7440  640229.0000 1
2015-12-25  2015-12-25  9.8550  9.8790  9.9270  9.8150  399845.0000 1
2015-12-28  2015-12-28  9.8950  9.5370  9.9190  9.5370  822408.0000 1
2015-12-29  2015-12-29  9.5450  9.6240  9.6320  9.5290  619802.0000 1
2015-12-30  2015-12-30  9.6240  9.6320  9.6400  9.5130  532667.0000 1

# 讀取stock.csv文件並將第一行做爲index,而且將000001做爲str類型讀取, 否則會被解析成整數
df2 = pd.read_csv("stock.csv", index_col=0, dtype={"Code": str})
df2.head()

簡單實例

這裏以處理web日誌爲例,也許不太實用 ,由於ELK處理這些綽綽有餘,不過喜歡什麼本身來也何嘗不可

分析access.log

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

日誌格式及示例

# 日誌格式
# 字段說明, 參考:https://ru.wikipedia.org/wiki/Access.log
%h%l%u%t \「%r \」%> s%b \「%{Referer} i \」\「%{User-Agent} i \」

# 具體示例
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

讀取並解析日誌文件

解析日誌文件

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+SPACE
line = '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()

將數據注入DataFrame對象

COLUMNS = ["Host", "Time", "Method", "Path", "Protocol", "status", "size", "User_Agent"]

field_lis = []
with open("access.log") as rf:
    for line in rf:
        # 因爲一些記錄不能匹配,因此須要捕獲異常, 不能捕獲的數據格式以下
        # 80.32.156.105 - - [27/Mar/2009:13:39:51 +0100] "GET  HTTP/1.1" 400 - "-" "-" "-"
        # 因爲重點不在寫正則表達式這裏就略過了
        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 = COLUMNS

def parse_time(value):
    try:
        return pd.to_datetime(value)
    except Exception as e:
        print(e)
        print(value)

# 將Time列的值修改爲pandas可解析的時間格式
log_df.Time = log_df.Time.apply(lambda x: x.replace(":", " ", 1))
log_df.Time = log_df.Time.apply(parse_time)

# 修改index, 將Time列做爲index,並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_Agent
Time                                
2009-03-22 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...

查看數據類型

# 查看數據類型
log_df.dtypes

Host                  object
Time          datetime64[ns]
Method                object
Path                  object
Protocol              object
status                object
size                  object
User_Agent            object
dtype: object

由上可知, 除了Time字段是時間類型,其餘都是object,可是Size, Status應該爲數字

def parse_number(value):
    try:
        return pd.to_numeric(value)
    except Exception as e:
        pass
        return 0

# 將Size,Status字段值改成數值類型
log_df[["Status","Size"]] = log_df[["Status","Size"]].apply(lambda x: x.apply(parse_number))
log_df.dtypes

Host                  object
Time          datetime64[ns]
Method                object
Path                  object
Protocol              object
Status                 int64
Size                   int64
User_Agent            object
dtype: object

統計status數據

# 統計不一樣status值的次數
log_df.Status.value_counts()

200    5737
304    1540
404    1186
400     251
302      37
403       3
206       2
Name: Status, dtype: int64

繪製pie圖

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

pandas從入門到上樓

查看日誌文件時間跨度

log_df.index.max() - log_df.index.min()

Timedelta('15 days 11:12:03')

分別查看起始,終止時間

print(log_df.index.max())
print(log_df.index.min())

2009-04-06 17:12:35
2009-03-22 06:00:32

按照此方法還能夠統計Method, User_Agent字段 ,不過User_Agent還須要額外清洗如下數據

統計top 10 IP地址

91.121.31.184     745
88.191.254.20     441
41.224.252.122    420
194.2.62.185      255
86.75.35.144      184
208.89.192.106    170
79.82.3.8         161
90.3.72.207       157
62.147.243.132    150
81.249.221.143    141
Name: Host, dtype: int64

繪製請求走勢圖

log_df2 = log_df.copy()
# 爲每行加一個request字段,值爲1
log_df2["Request"] = 1
# 每一小時統計一次request數量,並將NaN值替代爲0,最後繪製線性圖,尺寸爲16x9
log_df2.Request.resample("H").sum().fillna(0).plot(kind="line",figsize=(16,10))

pandas從入門到上樓

分別繪圖

分別對202,304,404狀態從新取樣,並放在一個列表裏面
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)
]

# 將三個dataframe組合起來
req_df = pd.concat(req_df_lis,axis=1)
req_df.columns = ["200", "304", "404"]
# 繪圖
req_df.plot(figsize=(16,10))

pandas從入門到上樓

參考連接

https://pandas.pydata.org/pandas-docs/stable/index.html

源代碼等資源文件

https://github.com/youerning/blog/tree/master/pandas

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