__init__.py

@app.route('/upload_data', methods=['POST'])
def upload_data():
    cur = conn.cursor()
    f = request.files['file']
    df = pd.DataFrame.from_csv(f, index_col=False)
    df.hashtags = df.hashtags.map(ast.literal_eval)
    screen_name = df.screen_name.unique()
    assert len(screen_name) == 1
    screen_name = screen_name[0]
    cur.execute('delete from tweets where screen_name = %s', [screen_name])
    for _, r in df.iterrows():
        cur.execute('insert into tweets ({}) values ({})'.format(
            ', '.join(df.columns.tolist()),
            ', '.join(['%s'] * df.shape[1])
        ), r)
    conn.commit()
    return jsonify({'success': True})