I want to upload various data from memory (contents of arrays, static html-code, ...) to a webserver via FTP.
This works for just one basic string 'Hello World':
from ftplib import FTP
import io
...
bio = io.BytesIO(b'Hello World')
ftp.storbinary('STOR index.html', bio)
However, I do not get it right to upload data like:
datalog = array([['Temperature', 0, 0], ['Humidity', 0, 0]])
html_code = '<head><title></title></head><body>display here</body></html>
You can upload files but not variables.
You can use BytesIO or StringIO to create file with your data and upload it. They have functions like normal file - ie. bio.write(html_code.encode()).
from ftplib import FTP
import io
text = '<head><title></title></head><body>display here</body></html>'
bio = io.BytesIO()
bio.write(text.encode())
bio.seek(0) # move to beginning of file
ftp.storbinary('STOR index.html', bio)
For datalog you can use module json to create string with all data
from ftplib import FTP
import io
import json
datalog = ([['Temperature', 0, 0], ['Humidity', 0, 0]])
text = json.dumps(datalog)
bio = io.BytesIO()
bio.write(text.encode())
bio.seek(0) # move to beginning of file
ftp.storbinary('STOR data.json', bio)
EDIT: Example with module csv which can't work directly with BytesIO but it needs string file.
from ftplib import FTP
import io
import csv
data = [['Temperature', 0, 0], ['Humidity', 0, 0]]
bio = io.BytesIO()
iow = io.TextIOWrapper(bio) # create String wrapper
csv_writer = csv.writer(iow) # create csv writer
csv_writer.writerows(data) # write all rows
iow.flush() # force String to send all from buffer to file (you can't use `iow.close()` for it)
bio.seek(0) # move to beginning of file
ftp.storbinary('STOR data.csv', bio)
# to see what is in bio
#bio.seek(0)
#print(bio.read())
