Flask-Excel 0.0.7

A flask extension that provides one application programming interface to read and write data in different excel file formats

Support the project

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If you are an individual, you are welcome to support me too on patreon and for however long you feel like to. As a patreon, you will receive early access to pyexcel related contents.

With your financial support, I will be able to invest a little bit more time in coding, documentation and writing interesting posts.

Known constraints

Fonts, colors and charts are not supported.

Introduction

Here is a typical conversation between the developer and the user:

User: "I have uploaded an excel file"
      "but your application says un-supported file format"
Developer: "Did you upload an xlsx file or a csv file?"
User: "Well, I am not sure. I saved the data using "
      "Microsoft Excel. Surely, it must be in an excel format."
Developer: "OK. Here is the thing. I were not told to support"
           "all available excel formats in day 1. Live with it"
           "or delay the project x number of days."

Flask-Excel is based on pyexcel and makes it easy to consume/produce information stored in excel files over HTTP protocol as well as on file system. This library can turn the excel data into a list of lists, a list of records(dictionaries), dictionaries of lists. And vice versa. Hence it lets you focus on data in Flask based web development, instead of file formats.

The idea originated from the common usability problem when developing an excel file driven web applications for non-technical office workers: such as office assistant, human resource administrator. The fact is that not all people know the difference among various excel formats: csv, xls, xlsx. Instead of training those people about file formats, this library helps web developers to handle most of the excel file formats by providing a common programming interface. To add a specific excel file format to you application, all you need is to install an extra pyexcel plugin. No code change to your application. Looking at the community, this library and its associated ones try to become a small and easy to install alternative to Pandas.

The highlighted features are:

1. excel data import into and export from databases

2. turn uploaded excel file directly into Python data structure

3. pass Python data structures as an excel file download

4. provide data persistence as an excel file in server side

5. supports csv, tsv, csvz, tsvz by default and other formats are supported via the following plugins:

A list of file formats supported by external plugins

Package name	Supported file formats	Dependencies	Python versions
pyexcel-io	csv, csvz [1], tsv, tsvz [2]		2.6, 2.7, 3.3, 3.4, 3.5, 3.6 pypy
pyexcel-xls	xls, xlsx(read only), xlsm(read only)	xlrd, xlwt	same as above
pyexcel-xlsx	xlsx	openpyxl	same as above
pyexcel-xlsxw	xlsx(write only)	XlsxWriter	same as above
pyexcel-ods3	ods	ezodf, lxml	2.6, 2.7, 3.3, 3.4 3.5, 3.6
pyexcel-ods	ods	odfpy	same as above
pyexcel-odsr	ods(read only)	lxml	same as above
pyexcel-text	(write only)json, rst, mediawiki, html, latex, grid, pipe, orgtbl, plain simple	tabulate	2.6, 2.7, 3.3, 3.4 3.5, 3.6, pypy
pyexcel-handsontable	handsontable in html	handsontable	same as above
pyexcel-pygal	svg chart	pygal	2.7, 3.3, 3.4, 3.5 3.6, pypy
pyexcel-sortable	sortable table in html	csvtotable	same as above
pyexcel-gantt	gantt chart in html	frappe-gantt	except pypy, same as above

In order to manage the list of plugins installed, you need to use pip to add or remove a plugin. When you use virtualenv, you can have different plugins per virtual environment. In the situation where you have multiple plugins that does the same thing in your environment, you need to tell pyexcel which plugin to use per function call. For example, pyexcel-ods and pyexcel-odsr, and you want to get_array to use pyexcel-odsr. You need to append get_array(…, library=’pyexcel-odsr’).

Footnotes

[1]

zipped csv file

[2]

zipped tsv file

This library makes information processing involving various excel files as easy as processing array, dictionary when processing file upload/download, data import into and export from SQL databases, information analysis and persistence. It uses pyexcel and its plugins:

1. to provide one uniform programming interface to handle csv, tsv, xls, xlsx, xlsm and ods formats.

2. to provide one-stop utility to import the data in uploaded file into a database and to export tables in a database as excel files for file download.

3. to provide the same interface for information persistence at server side: saving a uploaded excel file to and loading a saved excel file from file system.

Tested Flask Versions

Installation

You can install it via pip:

$ pip install Flask-Excel

or clone it and install it:

$ git clone https://github.com/pyexcel/Flask-Excel.git
$ cd Flask-Excel
$ python setup.py install

Usage

Here are some example codes:

from flask import Flask, request, jsonify
from flask.ext import excel

app=Flask(__name__)

@app.route("/upload", methods=['GET', 'POST'])
def upload_file():
    if request.method == 'POST':
        return jsonify({"result": request.get_array(field_name='file')})
    return '''
    <!doctype html>
    <title>Upload an excel file</title>
    <h1>Excel file upload (csv, tsv, csvz, tsvz only)</h1>
    <form action="" method=post enctype=multipart/form-data>
    <p><input type=file name=file><input type=submit value=Upload>
   </form>
    '''

@app.route("/export", methods=['GET'])
def export_records():
    return excel.make_response_from_array([[1,2], [3, 4]], "csv",
                                          file_name="export_data")

if __name__ == "__main__":
    app.run()

Development guide

Development steps for code changes

1. git clone https://github.com/pyexcel/Flask-Excel.git

2. cd Flask-Excel

Upgrade your setup tools and pip. They are needed for development and testing only:

1. pip install –upgrade setuptools pip

Then install relevant development requirements:

1. pip install -r rnd_requirements.txt # if such a file exists

2. pip install -r requirements.txt

3. pip install -r tests/requirements.txt

Once you have finished your changes, please provide test case(s), relevant documentation and update CHANGELOG.rst.

Note

As to rnd_requirements.txt, usually, it is created when a dependent

library is not released. Once the dependecy is installed (will be released), the future version of the dependency in the requirements.txt will be valid.

How to test your contribution

Although nose and doctest are both used in code testing, it is adviable that unit tests are put in tests. doctest is incorporated only to make sure the code examples in documentation remain valid across different development releases.

On Linux/Unix systems, please launch your tests like this:

$ make

On Windows systems, please issue this command:

> test.bat

How to update test environment and update documentation

Additional steps are required:

1. pip install moban

2. git clone https://github.com/pyexcel/pyexcel-commons.git commons

3. make your changes in .moban.d directory, then issue command moban

What is pyexcel-commons

Many information that are shared across pyexcel projects, such as: this developer guide, license info, etc. are stored in pyexcel-commons project.

What is .moban.d

.moban.d stores the specific meta data for the library.

Acceptance criteria

1. Has Test cases written

2. Has all code lines tested

3. Passes all Travis CI builds

4. Has fair amount of documentation if your change is complex

5. Agree on NEW BSD License for your contribution

License

New BSD License

Change log

0.0.7 - 20.07.2017

Updated

1. the intialization method has been modified. please call init_excel(app) before you do anything else. This change was made in order to apply for approved flask extension status. And by doing this change, it will support multiple Flask apps and only the app that was initialized with init_excel gets Flask-Excel and other apps in your BIG app won’t get affected.

0.0.6 - 22.06.2017

Updated

1. #22: support download

   file name in unicode(including Chinese texts)

0.0.5 - 21.08.2016

Updated

1. compatibility with pyexcel v0.2.2: automatic discovery of pyexcel plugins.

2. #15: file name may have more than one dot

0.0.4 - 15.01.2016

Updated

1. #8: set file name in response

0.0.3 - 01.07.2015

Updated

1. code refactoring. less code lines in Flask-Excel and more reusable code in pyexcel-webio

0.0.2 - 21.05.2015

Added

1. turn query sets into a response

0.0.1 - 22.01.2015

Mix pyexcel into Flask.request and bring more make_response functions.