FI is a Python library of functions for the financial independence (FI, FIRE) community. Functions can be run as standalone utilities on the command line or used in Python code. The FI library powers the auto-generated site FI Widgets which is a GUI representation of the library. It also powers FI API and is used in MMM Savings Rate.
This package is pip installable. To get the newest code use one of the commands below. FI requires python3. Use pip to install it if you're installing into a Virtualenv otherwise install with pip3. If you're a developer and you wish to contribute, see the installation instructions in the Developers section.
pip install git+https://github.com/bbusenius/FI.git#egg=FI
or
pip3 install -e git+https://github.com/bbusenius/FI.git#egg=FI
Pass the -e flag to retain the editable source.
The following functions are packaged in this library:
- annual_cost
- average_daily_spend
- buy_a_day_of_freedom
- coast_fi
- cost_of_costs
- cost_per_use
- days_covered_by_fi
- expected_gross_return
- fi_age
- fi_number
- future_value
- get_percentage
- hours_of_life_energy
- likely_real_return
- monthly_investment_income
- opportunity_cost
- percent_decrease
- percent_increase
- percent_return_for_percent
- pot_score
- real_hourly_wage
- redeem_points
- redeem_chase_points
- remaining_life_expectancy
- rule_of_72
- savings_rate
- spending_from_savings
- stock_returns
- take_home_pay
- turnover_costs
All functions can be run from the command-line or used in Python directly.
List available functions:
FI --help
To see how to run a function from the command-line, just open a terminal and invoke the command with --help options, e.g.:
coast_fi -h or coast_fi --help
This will display instructions on how to run the command.
Running the coast_fi command might look something like this:
coast_fi 800000 .07 62 40
Other functions are run in a similar way. Use -h or --help to see all the options.
By using variables and backticks, commands can be combined to produce more robust output. The following example shows how to calculate savings rate from money saved rather than money spent.
THP="$(take_home_pay 5215.71 417.27 514.09)"
savings_rate "${THP}" `spending_from_savings "${THP}" 2600`
Another useful example might be to calculate CoastFI using your "retire today" number, a projected inflation rate and a future value calculation.
coast_fi `future_value 800000 .03 1 22` .07 62 40
FI is written with type hints and relies on the built in typing module. This allows FI to be used more robustly in third party applications. Docstrings are considered forward facing since they are sometimes exposed to the public as on FI Widgets.
To install for development run the following command from the root of the cloned directory:
pip3 install -e .
python -m unittest tests.test_fi
Documentation is automatically generated from docstrings using Sphinx.
cd docs/
sphinx-apidoc -o source/ ../fi
make html