PLEASE NOTE: Though this script works perfectly as is, it is no longer maintained. The current implementation of this script is a functionally identical version written in Ruby.
Need to find the missing value in a ratio? This Python script will help you do that quickly.
Give numeric arguments in a series of three numbers with a ?, x, or any non-number to indicate the missing value.
Solve for x: 2/4 = x/10
~ python ratio-calculator.py 2 4 ? 10
5
Two decimal places are included in default usage. Trailing zeroes and decimal points in the case of integers like the 5 above will be trimmed. See the -r flag below to change the number of included decimal places.
Round the result to [number] decimal places. Default: 2
~ python ratio-calculator.py 12 345 ? 678
23.58
~ python ratio-calculator.py 12 345 ? 678 -r 6
23.582609
By default, integers are returned without a decimal point and two trailing zeroes, even though values are calculated as floating point numbers and rounded to two decimal places.
Use this flag if you want two empty decimal places to be returned.
~ python ratio-calculator.py 2 4 ? 10 -d
5.00
Instead of just returning the missing number, return the entire ratio as a string with the missing number plugged in.
~ python ratio-calculator.py -v 2 4 ? 10
2/4 [5]/10
Returns result without a newline at the end. Useful for piping into other programs.
For example, copying the result to the clipboard on OS X:
~ python ratio-calculator.py 2 4 ? 10 -w | pbcopy
Use the --without_newline flag to remove the newline that would otherwise be printed to the terminal, then pipe the result to pbcopy to copy the result to your clipboard, ready for pasting. (This only works on OS X.)
~ python ratio-calculator.py --without_newline 2 4 ? 10 | pbcopy
If you want to see the result as well as copy to the clipboard (source):
~ python ratio-calculator.py --without_newline 2 4 ? 10 | pbcopy | tee /dev/tty
5
- Justin Falcone and Cody Robbins for code review