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matplotlib绘制
Sometimes you want to see the number of registered users in your Django website over time. Fortunately Django stores the registration date of a user model instance in the date_joined field, so we can plot it.
有时您想查看一段时间内Django网站中已注册用户的数量。 幸运的是，Django将用户模型实例的注册日期存储在date_joined字段中，因此我们可以对其进行绘制。
先决条件 (Prerequisites)
You need an installation of and . You can install the libraries using pip:
您需要安装和 。 您可以使用pip安装库：
$ pip install numpy$ pip install matplotlib
It is important that you install before you install , otherwise compiling the latter won’t work. You can also use your system package manager to install them instead, if you prefer that.
在安装之前，请先安装 ，这一点很重要，否则编译后者将无法进行。 如果愿意，也可以使用系统软件包管理器来安装它们。
添加管理命令 (Adding a Management Command)
Now create a new Django management command. We could also do this as a standalone script, but by creating a management command we have easier access to the database.
现在创建一个新的Django管理命令。 我们也可以将其作为独立脚本来执行，但是通过创建管理命令，我们可以更轻松地访问数据库。
$ mkdir -p/management/commands$ touch /management/__init__.py$ touch /management/commands/__init__.py$ touch /management/commands/plot_user_registrations.py
Now add the following code to your plot_user_registrations.py file:
现在，将以下代码添加到您的plot_user_registrations.py文件中：
from from optparse optparse import import make_optionmake_optionfrom from django.core.management.base django.core.management.base import import BaseCommandBaseCommandfrom from django.contrib.auth django.contrib.auth import import get_user_modelget_user_modelimport import numpy numpy as as npnpimport import matplotlib.pyplot matplotlib.pyplot as as pltpltfrom from matplotlib.dates matplotlib.dates import import date2numdate2numclass class CommandCommand (( BaseCommandBaseCommand ): ): help help = = 'Plot user registrations. Use --save option to save the plot to a png file.' 'Plot user registrations. Use --save option to save the plot to a png file.' option_list option_list = = BaseCommandBaseCommand .. option_list option_list + + ( ( make_optionmake_option (( '--save''--save' , , actionaction == 'store''store' , , destdest == 'save''save' , , helphelp == 'Save the graph as a png to the specified location''Save the graph as a png to the specified location' ), ), ) ) def def handlehandle (( selfself , , ** argsargs , , **** optionsoptions ): ): # Get user join dates # Get user join dates User User = = get_user_modelget_user_model () () datetimes datetimes = = UserUser .. objectsobjects .. values_listvalues_list (( 'date_joined''date_joined' , , flatflat == TrueTrue ) ) .. order_byorder_by (( 'date_joined''date_joined' ) ) dates dates = = mapmap (( lambda lambda dd : : dd .. datedate (), (), datetimesdatetimes ) ) # Get some auxilliary values # Get some auxilliary values min_date min_date = = date2numdate2num (( datesdates [[ 00 ]) ]) max_date max_date = = date2numdate2num (( datesdates [[ -- 11 ]) ]) days days = = max_date max_date - - min_date min_date + + 1 1 # Initialize X and Y axes # Initialize X and Y axes x x = = npnp .. arangearange (( min_datemin_date , , max_date max_date + + 11 ) ) y y = = npnp .. zeroszeros (( daysdays ) ) # Iterate over dates, increase registration array # Iterate over dates, increase registration array for for date date in in datesdates : : index index = = intint (( date2numdate2num (( datedate ) ) - - min_datemin_date ) ) yy [[ indexindex ] ] += += 1 1 y_sum y_sum = = npnp .. cumsumcumsum (( yy ) ) # Plot # Plot pltplt .. plot_dateplot_date (( xx , , y_sumy_sum , , xdatexdate == TrueTrue , , ydateydate == FalseFalse , , lsls == '-''-' , , msms == 00 , , colorcolor == '#16171E''#16171E' ) ) pltplt .. fill_betweenfill_between (( xx , , 00 , , y_sumy_sum , , facecolorfacecolor == '#D0F3FF''#D0F3FF' ) ) pltplt .. titletitle (( 'Registered Users''Registered Users' ) ) pltplt .. rcrc (( 'font''font' , , sizesize == 88 ) ) if if optionsoptions [[ 'save''save' ]: ]: pltplt .. savefigsavefig (( optionsoptions [[ 'save''save' ]) ]) elseelse : : pltplt .. showshow ()()
用法 (Usage)
Now you can call your new management command:
现在，您可以调用新的管理命令：
$ python manage.py plot_user_registrations
This will open a new window containing the plot. You can also save it to a png file instead:
这将打开一个包含该图的新窗口。 您也可以将其保存为png文件：
$ python manage.py plot_user_registrations --save users.png
If you want, you can tweak the configuration in order to change the plot style / colors / etc. If you find some nice improvements, feel free to leave a comment below!
如果需要，可以调整配置，以更改样式/颜色/等。如果发现一些不错的改进，请随时在下面留下评论！
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matplotlib绘制
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