Work with excel files in memory¶
Excel files in memory can be manipulated directly without saving it to physical disk and vice versa. This is useful in excel file handling at file upload or in excel file download. For example:
>>> import pyexcel
>>> content = "1,2,3\n3,4,5"
>>> sheet = pyexcel.get_sheet(file_type="csv", file_content=content)
>>> sheet.csv
'1,2,3\r\n3,4,5\r\n'
file type as its attributes¶
Since version 0.3.0, each supported file types became an attribute of the Sheet and Book class. What it means is that:
- Read the content in memory
- Set the content in memory
For example, after you have your Sheet and Book instance, you could access its content in a support file type by using its dot notation. The code in previous section could be rewritten as:
>>> import pyexcel
>>> content = "1,2,3\n3,4,5"
>>> sheet = pyexcel.Sheet()
>>> sheet.csv = content
>>> sheet.array
[[1, 2, 3], [3, 4, 5]]
Read any supported excel and respond its content in json¶
You can find a real world example in examples/memoryfile/ directory: pyexcel_server.py. Here is the example snippet
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 | def upload(): if request.method == 'POST' and 'excel' in request.files: # handle file upload filename = request.files['excel'].filename extension = filename.split(".")[-1] # Obtain the file extension and content # pass a tuple instead of a file name content = request.files['excel'].read() if sys.version_info[0] > 2: # in order to support python 3 # have to decode bytes to str content = content.decode('utf-8') sheet = pe.get_sheet(file_type=extension, file_content=content) # then use it as usual sheet.name_columns_by_row(0) # respond with a json return jsonify({"result": sheet.dict}) return render_template('upload.html') |
request.files[‘excel’] in line 4 holds the file object. line 5 finds out the file extension. line 13 obtains a sheet instance. line 15 uses the first row as data header. line 17 sends the json representation of the excel file back to client browser.
Write to memory and respond to download¶
1 2 3 4 5 6 7 8 9 10 11 12 | data = [ [...], ... ] @app.route('/download') def download(): sheet = pe.Sheet(data) output = make_response(sheet.csv) output.headers["Content-Disposition"] = "attachment; filename=export.csv" output.headers["Content-type"] = "text/csv" return output |
make_response is a Flask utility to make a memory content as http response.
Note
You can find the corresponding source code at examples/memoryfile
Relevant packages¶
Readily made plugins have been made on top of this example. Here is a list of them:
framework | plugin/middleware/extension |
---|---|
Flask | Flask-Excel |
Django | django-excel |
Pyramid | pyramid-excel |
And you may make your own by using pyexcel-webio