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Python psycopg2 cursor.fetchall() returns empty list but cursor.rowcount is > 1

I am getting an issue here:
conn = psycopg2.connect(conn_string)
cursor = conn.cursor()
sql = """
SELECT DISTINCT (tenor_years)
FROM bond_pnl
WHERE country = '%s'
""" % country
cursor.execute(sql)
print(cursor.fetchall())
print(cursor.rowcount)
It gives the following output:
[]
11
which means that cursor.rowcount is 11 but cursor.fetchall() is empty list. I have already tried doing this:
conn.set_session(readonly=True, autocommit=True)
and this solution as well :Click to see
Any help regarding this will be appreciated.
EDIT: Just came across another thing, this code when executed first time, works fine. But executing it again(second, third, ...n execution) gives the above behavior.

I also faced the same issue. I figured out that,
Might be while debugging, we are allowing some fraction of time after connection has been made
#conn = psycopg2.connect(conn_string)
#cursor = conn.cursor()
By the time we hit the execution button for the next line (which contains the query), database is timed out and it is returning empty list.
If anyone has any other logic for why this is happening please do share.

After trying different solution, I have figured out that the problem described in the question arises when I execute it in "Debugging Mode" in pycharm. But on the other hand if I execute the code in "Run Mode" in pycharm , it returns the right expected output (a list with 11 elements):
[a,b,c,d,e,f,g,h,i,j,k]
Not sure about the exact reason for it but somehow the cursor was breaking somewhere when run in "Debugging Mode".
If anyone describes the exact reason, It ll be highly appreciated.

SQL query returning None in Python script while there are records in table

I am trying to write a simple Python script that gets data from an API, stores it in a MySQL database, and performs some calculations on that data. I try fetch all data from a table where I just inserted some, but that query keeps returning None.
Part that doesn't work:
import MySQLdb
db = MySQLdb.connect("localhost", "stijn", "password", "GW2")
curs = db.cursor()
curs.execute("select gw2_id, naam from PrijzenMats")
for record in curs.fetchall():
curs2 = db.cursor()
curs2.execute("insert into MaterialPrijzenLogs(mat,prijs,tijd) values(%s, %s, %s)", (record[1], prijs, tijd))
db.commit()
curs2.execute("select prijs from MaterialPrijzenLogs")
top10 = len(curs2.fetchall())/10
print(str(len(curs2.fetchall())))
That last print keeps giving 0, even when I populate the table before running the script.
Full code

I solved the problem. Apparently when you call fetchall() it doesn't just get the data from the cursor like a normal getter in Java would do, but it also deletes the data from the cursor. In my code I called fetchall() first to initialize a variable, and after that I tried to print the length of curs2.fetchall(), which had become 0 at that point. This can be easily solved by adding something like myList = curs2.fetchall() directly after curs2.execute("select prijs from MaterialPrijzenLogs") and using the myList variable in the rest of the code instead of curs2.fetchall(). I did not include the declaration of that top10 variable in the code example in my original question because I thought it had nothing to do with the problem. I edited the question so future readers can easily understand the problem.

Python Update in MySQL

I've been struggling to get this really simple query to actually work in Python. I am a complete python newb, and strings seem to be handled a lot differently than what I am accustomed to.
The query I am trying...
cur = db.cursor()
cur.execute("SELECT bluetooth_Id FROM student_Data")
data = cur.fetchall()
for row in data :
bluetoothId=row[0]
result=bluetooth.lookup_name(bluetoothId,timeout=5)
print(result)
if(result != None):
cur.execute("UPDATE student_Data SET attendance = 1 WHERE bluetooth_Id= %s",(bluetoothId))
print("UPDATE student_Data SET attendance = 1 WHERE bluetooth_Id= %s",(bluetoothId))
What seems to be the problem is that my actual SQL query is not correctly formatted.. I know this because that last print statement returns this
('UPDATE student_Data SET attendance = 1 WHERE bluetooth_Id= %s', 'th:is:is:my:bt:id')
and of course that id is not actually the id it returns... I didn't want to give that to you :)
I am following examples to the dot, and not getting anywhere.. my bluetooth is on, the program sees my bluetooth id, it processes through the list of ids already in my mysql table, but it isn't updating any records.
and I did check to make sure I entered my id in the mysql table correctly, so that is not the problem either!
Update
I was able to get the correct MySQL query created using this:
cur.execute("UPDATE student_Data SET attendance = 1 WHERE bluetooth_Id = '%s"%(bluetoothId)+"'")
which creates
UPDATE student_Data SET attendance = 1 WHERE bluetooth_Id = '11:11:11:11:11:11'
but the MySQL table still isn't updating correctly.. I'll have to look into seeing why that is...

The solution was this:
cur.execute("UPDATE student_Data SET attendance = 1 WHERE bluetooth_Id = '%s"%(bluetoothId)+"'")
and then I had to add
db.commit()
After the execute, in order to actually commit the changes to the MySQL table.
Thanks all for the help:)
Python mySQL Update, Working but not updating table

You need to do this:
cur.execute("UPDATE student_Data SET attendance = 1 WHERE bluetooth_Id= %s"%(bluetoothId))
If you are doing substitution, you need a % instead of a comma

Multiqueries with python/mysql

I'm using MysqlDB. Does it provide a way to execute multiple SELECT queries like mysqli_multi_query does? If not, is there a python library that would allow that?
There is executemany, but that's not what I'm looking for. I'm working with Sphinx and trying to get its batch queries to work.

I spent some time to dig in the source code of MySQLdb and the answer is YES you can do multiple queries with it:
import MySQLdb
db = MySQLdb.connect(user="username", db="dbname")
cursor = db.cursor()
batch_queries = '''
SELECT * FROM posts WHERE id=1;
SELECT * FROM posts WHERE id=2;
'''
cursor.execute(batch_queries)
print cursor.fetchone()
while cursor.nextset(): # iterate to next result set if there is any
print cursor.fetchone()
cursor.close()
Tested successfully in my localhost. Hope it helps.

How to return cursor in Python (sqlite)?

Using Python (2.7)and sqlite (3) I am trying to copy results of a query into a table.
Because the result of the query is very large, I would like to use “fetchmany” in batches.
The query works fine, retrieving the results in the batches as well.
The problem is that when I try to copy the results in the table, it stops after the first batch.
I suspect that the problem is the place of the cursor.
How does one returns the cursor in python ?
P.S: I have seen here many posting about cursor (closing) but haven't seen the answer to my question. Please note also that I am new to Python, so apologies if the question is trivial.
Here pieces of my codes: (example)
import sqlite3
dbLocation = 'P:/XXX/db1.db'
connection = sqlite3.connect(dbLocation)
cursor = connection.cursor()
strSQLStatement = """
SELECT
whatever1,
whaterver2
from wherever
LIMIT 10"""
cursor.execute(strSQLStatement)
#the following codes works
# printing the 10 results
while True:
results = cursor.fetchmany(2)
if not results:
break
print results
#the following codes does NOT work
# Only 2 results are processed
while True:
results = cursor.fetchmany(2)
if not results:
break
print results
cursor.executemany ('INSERT INTO NewTable (?,?)',results)
connection.commit()

Your call to executemany() on the original cursor clobbers what was there before. Create a second cursor to perform the insert.