Newbie questions to use Backtrader in 'real world' scenarios.

rustyg

Hi,

I've been tinkering with Backtrader for the past week or two, and I've watched some YouTube videos as well, but I have a couple of questions which I can't find the answers to on the Backtrader site or here.

I think they are some newbie questions that would really help me use Backtrader in a more 'real world' scenario for the hobbyist investor.

Here are the questions (go easy on me):

How do I invest a certain sum of money rather than a fixed stake each time? I think I need to access the current price prior to buying then calculate the number of shares I can purchase based on my cash reserve.
How can I set the trade commission as a fixed amount rather than a percentage, e.g. $10? Here in the UK, the brokers tend to charge a fixed sum rather than commission.
How do I reinvest all my cash each time rather than a fixed stake? Or reinvest only the profit? In real life this is something I do, I never invest based on a number of shares each time.
How do I access user defined variables in my strategy class from the main script? I want to return particular information/results back, that I can then manipulate. For example with the optimization example I want to store each result in a list then analyse the list once each test case has been executed.

Thanks in advance.

run-out

@rustyg said in Newbie questions to use Backtrader in 'real world' scenarios.:

How do I invest a certain sum of money rather than a fixed stake each time? I think I need to access the current price prior to buying then calculate the number of shares I can purchase based on my cash reserve.

You can create a custom sizer and the current cash info is available to then divide by your security price to get units.

@rustyg said in Newbie questions to use Backtrader in 'real world' scenarios.:

How can I set the trade commission as a fixed amount rather than a percentage, e.g. $10? Here in the UK, the brokers tend to charge a fixed sum rather than commission.
Look here
If margin is something else, it is considered the operations are happenning on a futures like intstrument and commission is a fixed price per size contracts

@rustyg said in Newbie questions to use Backtrader in 'real world' scenarios.:

How do I reinvest all my cash each time rather than a fixed stake? Or reinvest only the profit? In real life this is something I do, I never invest based on a number of shares each time.

You can check cash value in the broker in each next and decide if it's enough to invest.

@rustyg said in Newbie questions to use Backtrader in 'real world' scenarios.:

How do I access user defined variables in my strategy class from the main script? I want to return particular information/results back, that I can then manipulate. For example with the optimization example I want to store each result in a list then analyse the list once each test case has been executed.

Analyzers