kalk 0.14.0

a simple cli RPN calculator written in Python

installation

Requires Python 3.9+.

pip install kalk

Usage

After installation run kalk from your terminal.

In RPN syntax one would first enter the operands and then the operator:

>>> 1
1
>>> 2
2
>>> +
3

You may also enter the operands and the operator in one line, just use space to separate them:

>>> 41 1 +
42

(tip: the space is not needed when the syntax is not ambiguous.)

Kalk tries to follow Python’s syntax. Similar to Python, ** is the power operator and ^ is bitwise XOR:

>>> 3 3 **
27
>>> 3 3 ^
0

Kalk ignores , (thousands separator) within numbers.

>>> 1,234 1 +
1,235

Most of the functions defined in Python’s math and statistics modules are supported.

>>> 6 lgamma
4.787491742782047

and many more.

You can even do datetime and timedelta calculations:

>>> "2023-03-22" dt
2023-03-22 00:00:00
>>> 2 days 3 hours +
2 days, 3:00:00
>>> -
2023-03-19 21:00:00

Start a substack (a list) with a [ and end it with a ]. Some functions require lists as argument. For example to calculate the distance between two points or sum of some numbers:

>>> [2 -1] [-2 2] dist
5.0
>>> [0 0 0] [1 1 1] dist
1.7320508075688772
>>> [1 1 1] sum
3

Handy operators:

• <> swaps the place of the last two values in the stack.

• c clears the stack

• cp copies the last result to clipboard.

• del deletes the last n + 1 values from from the stack with n being the last value in the stack.

• e adds Euler’s number to the stack

• pi adds the pi constant to the stack

• pst pastes the contents of clipboard and evaluates it.

• a the last answer

• s prints the stack

• sto stores the value before the last in storage using the last stack value as the key.

• rcl recalls the value in storage using the last stack value as the key.

• h prints a list of all operators. (still needs lots of refinements.)

• ? prints the docstring of the operator given as a string. For example "<>" ? will print the help string on swap. Note that not all functions have documentation yet.