Group Operator in OpenERP for Grouping

When defining search views, we may sometimes need to add "group_by" filters for showing the list view in groups. For example,

 The image shown above is from sale order. Here the list view grouping is done by user_id(salesman). Let focus on Demo User. Here four sale orders are created by the Demo user.

This is the extended view. Here the name written in bold is the group name. Now focus on the Untaxed Amount and Total and the value writen inside the red marker. The value shown inside the red marker are actually the sum of float or integer fields comes under the group. Here comes the use of group operator. The default value for group_operator is sum. Thats why we are getting the sum when grouping. To change the default value goto our python file, in the field definition add group_operator="avg" to get the average, group_operator="min" to get the minimum value from the group, group_operator="max" to get the maximum value from the group.

For example,

 Here I added group_operator="avg" in the untaxed amount. Now we have to verify it by grouping.

 Here the value shown inside the red marker is the average of that group. Now you can try the min and max by changing the group_operator value.

Creating an Excel file or a spreadsheet using Python's xlwt (xlutils) module

A spreadsheet is used to simulates a paper accounting worksheet. It displays multiple cells usually in a two-dimensional matrix or grid consisting of rows and columns. We have so many reporting software s that will simply create spreadsheets. But the problem is, these reporting software s may not support on all systems and also take lot of CPU time. Then arise an idea to use some method to create spreadsheet from my python code. Then I found about the module xlutils in python.

XLUTILS module contain packages for reading from(xlrd) and writing to(xlwt) excel files. Since I only need the package to write to excel file I'm installing the xlwt package.

Installation
We can install any python package to our repository using pip, pip is an easy way to install python packages.
To install pip
omal@zbeanz:~$sudo apt-get install python-pip
After installing pip you can install python packages by
omal@zbeanz:~$sudo pip install xlwt
This will install xlwt package to python modules

 Now in our python code,

to import the package functionality to the our program.

We can define the title, header, number, date, and normal style using xlwt.easyxf(). For example title style is given below

We can define as many styles we want. We can also define how the border should appear. For example,

After defining the styles we can now define the workbook. Workbook is actually what we view in our spreadsheet. To define workbook,

A spreadsheet may contain more than one sheet, so to add sheets,

Now we can start adding data to the sheet we have created.  To write data to the 'sheet1' use the reference ws and ws.write(row, column, 'Value or text',style). For example:

To change the width and height of a cell,

 We can add complete data to the spreadsheet by writing and changing the height and width according to our need. After completing this we can save the workbook to a buffer. So First define the buffer and then save the workbook to the  buffer. This doesn't complete the process.

Now we have to encode the data in the buffer and write it to a file say 'test.xls'. To encode the data in the buffer import base64 module. Now open the file test.xls to view our excel file we have created.

I have not mentioned the last few steps (from encoding) so that you can try it out.