PiggyBank/README.md

Keep track of your piggy bank.

Every time you put coins in or take them out of your piggy bank, write here down
how much did you put or take. So you won't have to spend time counting them when
you decide to take them all out.

Yes, only coins, no banknots. Well, you actually can easily add support for
banknots, but table will become indeed wide.

# Backstory

Many years ago I wrote a little script to store info on how much coins I have
in my piggy bank. It used SQLite 3 database for it and was hardcoded to rubles.

This year I came up with an idea that it would be good to learn on how to make
packages for Python. And with no better ideas I took my piggy bank script to be
rewritten to support any currency. Database was thrown away and its place was
took by a simple text format.

# Usage

This is a CLI program that is broken down to three separate programs:

- `piggybank-put` — puts coins in a piggy bank and create a new one if
  there is no such file;
- `piggybank-take` — takes coins from an existsing piggy bank file;
- `piggybank-show` — shows summarised information on a piggy bank and,
optionally, print a list of transactions.

## Common flags

```bash
piggybank-* [(-h | --help) | (-v | --version) | --list-currencies]
```

`--help` to show help on what commands you can use.

`--version` to show version of program.

`--list-currencies` to show what currencies supported and which one is default.

## How to put coins in

```bash
piggybank-put <file> [-r | --reverse] <coins> [(-c | --currency) <currency>]
```

Here's how to put coins in a piggybank file. It will also create a file if it
doesn't exist.

`<file>` is a name of a piggy bank file wich may not have a .pb extension at the
end, it will be added automatically.

`<coins>` is a set of coins' counts separated with space character. For example:
0 0 0 5 0 4 6 7. By default trailing zeroes will be added from the
left. So if you wrote something like 6 0 5 12 then it will be complemented to
0 0 0 0 6 0 5 12 if currency has 8 coins.

`--reverse` flag reverses the order of coins. By default they come from least
significant face value to the most significant one and as stated above being
complemented from left so a set shorter than number of coins in a currency,
e.g. 5 8 4 will be interpreted as 0 0 0 0 0 5 8 4. And this flag will make it
to be interpreted as 5 8 4 0 0 0 0 0. It is convenient if you want to add only
coins of low face value (e.g. cents or kopeks).

`--currency` parameter specifies the currency of a new piggy bank. It will not
change currency of an existing piggy bank.

### Examples:

```bash
piggybank-put example.pb 7 4 3 0 5 -c euro
piggybank-put example -r 0 4 6
```

## How to take coins out

```bash
piggybank-take <file> [-r | --reverse] <coins>
```

All the parameters are explained above. `--currency` flag is not applicable
here.

### Examples:

```bash
piggybank-take example.pb -r 0 0 4
```

## How to see what do you have

```bash
piggybank-show <file> [-t | --transactions]
```

Without `-t` flag only summarised information will be printed. `--transactions`
flag tells the program to print out all the transactions stored in a piggy bank.

### Examples:

```bash
piggybank-show example.pb -t
```