runs a dax query against SSAS and returns a dataframe

dax_to_dataframe.py

import clr
import pandas as pd
from tqdm import tqdm
clr.AddReference("System.Data")
import System.Data.OleDb as ADONET

def handle_oledb_field(f):
    mytype=str(type(f))
    if mytype == "<class 'System.DBNull'>": 
           return None
    if mytype == "<class 'int'>": 
           return int(f)        
    if mytype == "<class 'System.Decimal'>": 
           return float(f.ToString())
    if mytype == "<class 'str'>": 
           return str(f)
    raise "Unknown Type " + mytype   

def dax_to_dataframe(daxcmd):
    if "connection" not in dax_to_dataframe.__dict__: dax_to_dataframe.connection = None
    connStr = r"Provider=MSOLAP;Persist Security Info=True;Initial Catalog=DBNAME;Data Source=SERVERNAME"

    if dax_to_dataframe.connection is None:
        connection = ADONET.OleDbConnection(connStr)
        connection.Open()

    command = connection.CreateCommand()
    command.CommandText = daxcmd
    reader = command.ExecuteReader()
    schema_table = reader.GetSchemaTable()

    #schema_table rows are query result columns
    columns = []
    for r in schema_table.Rows:
        columns.append(r['ColumnName'])

    rows = [None] * reader.get_RecordsAffected()
    for x in tqdm(range(0, reader.get_RecordsAffected())):
        reader.Read()
        #https://docs.microsoft.com/en-us/dotnet/api/system.typecode?view=netframework-4.7.2
        #but ints dont have them
        #rows[x] = list( [ reader[c] if reader[c].GetTypeCode() != 2 else None for c in columns] )
        rows[x] = list ( [ handle_oledb_field(reader[c]) for c in columns ] )
         
    #connection.Close()
    df = pd.DataFrame.from_records(columns=[c.replace('[', '_').replace(']', '_') for c in columns], data=rows, coerce_float=True)
    del rows
    del reader
    return df