Because I couldn't find any good suggestions or code samples, I implemented my own solution. Thank you so much to the Stackoverflow community for some ideas which I used in my code. I put the code to GitHub (pyFTPclient) due to the size of the code(~ 120 lines).
I tested the solution on bad quality network (include 3G mobile internet) and it was work ok for me. But of course it may have some bugs.
I will appreciate any comments or suggestions. Thank you in advance.