Extract PI OSIsoft Monthly Interval in Python - pandas

Question

I am trying to extract the sum of PI data from OSIsoft 10m (10 minute) data in a one (1) month interval using Python pandas. However, I either get an error from OSIsoft or Python when I choose the internal notation as "M" for OSIsoft or "1mo" for python. Neither notation seems to work w/out an error. I have a function that calls the interval of data to plot and save and this works for intervals of "1d", "30d", "1w", "1y" for example but I cannot get the sum of data for each 1-month interval. Is it a conflict of how python requires a description of "month" with an "M" and OSISoft that requires "1mo"?? thank you, Here is my code:
def get_tag_history2(tagname, starttime, endtime, interval="10m"):
# pull historical data
tag = PIPoint.FindPIPoint(piServer, tagname)
# name = tag.Name.lower()
timerange = AFTimeRange(starttime, endtime)
span = AFTimeSpan.Parse(interval)
#summariesvalues
summaries = tag.Summaries(timerange, span, AFSummaryTypes.Average, AFCalculationBasis.TimeWeighted, AFTimestampCalculation.Auto)
recordedValuesDict = dict()
for summary in summaries:
for event in summary.Value:
dt = datetime.strptime(
event.Timestamp.LocalTime.ToString(),'%m/%d/%Y %I:%M:%S %p')
recordedValuesDict[dt] = event.Value
# turn dictionary into pd.DataFrame
df = pd.DataFrame(
recordedValuesDict.items(), columns=['TimeStamp', 'Value'])
#Send it to a dateTime Index then set the index
df['TimeStamp'] = pd.to_datetime(df['TimeStamp']) + pd.Timedelta(interval)
df.set_index(['TimeStamp'], inplace=True)
return df
if __name__ == '__main__':
"""
Set inputs
"""
pitags = ['JC1.WF.DOMINA.ProdEffective','HO1.WF.DOMINA.ProdEffective','BC1.WF.DOMINA.ProdEffective']
start_time = '2020-01-01 00:00'
end_time = '2022-01-01 00:00'
interval = "M"
"""
Run Script
"""
connect_to_Server('PDXPI01')
output = pd.DataFrame()
for tag in pitags:
values = get_tag_history2(
tag, start_time, end_time, interval=interval)
output[tag] = values['Value']
for i, col in enumerate(output.columns):
output[col].plot(fig=plt.figure(i))
plt.title(col)
plt.show()
The error when using interval = "1mo" is --- >
ValueError: invalid unit abbreviation: mo
The error when using interval = "M" is --- >
FormatException: The 'M' token in the string 'M' was not expected.
at OSIsoft.AF.Time.AFTimeSpan.FormatError(String input, Char token, Boolean throwErrors, AFTimeSpan& result)