All, I need to iterate through OptionChains class members to select individual chains based upon criteria of Right/Expiry/Strike.  

I found this Python code in the Tutorial: Applied Options:Iron Condor.  Howerver, it appears that in C# we do not have the ability to use array indexing to select a member of an OptionsChains class. In Python we see the use of such indexing

 

def TradeOptions(self,slice):
# If there is undelying assets in portfolio at expiration, liquidate the stocks in order to roll into new contracts
if self.Portfolio["GOOG"].Quantity != 0:
self.Liquidate()

if not self.Portfolio.Invested and self.Time.hour != 0 and self.Time.minute != 0:
for i in slice.OptionChains:
chain = i.Value
contract_list = [x for x in chain]
# if there is no optionchain or no contracts in this optionchain, pass the instance
if (slice.OptionChains.Count == 0) or (len(contract_list) == 0):
return

# sorted the optionchain by expiration date and choose the furthest date
expiry = sorted(chain,key = lambda x: x.Expiry)[-1].Expiry
# filter the call and put options from the contracts
call = [i for i in chain if i.Expiry == expiry and i.Right == 0]
put = [i for i in chain if i.Expiry == expiry and i.Right == 1]

# sorted the contracts according to their strike prices
call_contracts = sorted(call,key = lambda x: x.Strike)
put_contracts = sorted(put,key = lambda x: x.Strike)
if len(call_contracts) == 0 or len(put_contracts) == 0 : continue

otm_put_lower = put_contracts[0]
otm_put = put_contracts[10]
otm_call = call_contracts[-10]
otm_call_higher = call_contracts[-1]
self.trade_contracts = [otm_call.Symbol,otm_call_higher.Symbol,otm_put.Symbol,otm_put_lower.Symbol]
When I try this in C# the error message is "Cannot apply Indexing with [] to an expression of type OptionContract".... it's an extension of IEnumerable. I cannot find a way to select the nth member.