jneug / drang-run

A simple command line tool to create sequences of numbers.

drang-run

A simple command line tool to print sequences of numbers.

drang-run is comparable to jot or seq, but with a more intuitive interface. It was inspired (and named after) a post by Dr. Drang.

Installation

Just install like any other package:

$ pip3 install drang-run

This will install the run command.

$ run --version
run, version 0.4.4

Usage

Basic usage includes up to three arguments:

run [START] STOP [STEP]

[START] and [STEP] are optional and default to 1.

$ run 4
1
2
3
4
$ run 5 8
5
6
7
8
$ run 0 10 3
0
3
6
9

Reverse the sequence with -r:

$ run 4 -r
4
3
2
1

Or switch the arguments:

$ run 4 1 -1
4
3
2
1

Note

run will try to guess the correct direction for the sequence based on the arguments. The example above could be simply written as run 4 1.

For conflicting sets of arguments, the values for START and STOP will take precedence over STEP. So run 1 4 -1 will be the same as run 1 4 1.

The only exeption to this is STEP = 0 which will cause an error.

This also means that run will almost never produce an empty output because at least START will be part of the sequence.

Format the output with --format. The option accepts any kind of Python format string.

$ run 998 1002 --format "{: >4}."
 998.
 999.
1000.
1001.
1002.

You can use decimals for [START], STOP and [STEP]:

$ run 1.1 1.5 .15
1.1
1.25
1.4

Note

If at least one argument is a decimal, the output will be formatted as decimals as well.

$ run 1.0 4 1
1.0
2.0
3.0
4.0

You can always change this by using appropriate format strings.

$ run 1.0 4 1 --format "{:g}"
1
2
3
4

Using letters for [START] and STOP will generate character sequences:

$ run d g
d
e
f
g

By default, the items are separated by a newline character \n, but you can change this with -s:

$ run d g -s "\t"
d       e       f       g

Run additional sequences with --also START STOP STEP:

$ run 1 2 --also 3 4 1
1-3
1-4
2-3
2-4

Note

--also requires all three arguments to be present.

Of course, this can be used with characters and be formatted:

$ run 1 2 --also b c 1 --format "{0:02}. {1}_{1}"
01. a_a
01. b_b
02. a_a
02. b_b

Note

The sequences can be referenced in the format string by order of appearance. -r will reverse all sequences.

Since version 0.4.0 you can define variables with the --def option. A variable can be set to a simple arithmetic expression that is evaluated with the current counter values. Similar to the format string (-f) the counters can be referenced with {0}, {1} and so on. All defined variables are initialized with 0 and can be used in other expressions, even in the definition of themselves.

$ run 4 --also 1 3 1 --def sum "{0}+{1}" --def akk "{akk}+{sum}" --format "{0} + {1} = {sum} ({akk})"
1 + 1 = 2 (2)
1 + 2 = 3 (5)
1 + 3 = 4 (9)
2 + 1 = 3 (12)
2 + 2 = 4 (16)
2 + 3 = 5 (21)
3 + 1 = 4 (25)
3 + 2 = 5 (30)
3 + 3 = 6 (36)
4 + 1 = 5 (41)
4 + 2 = 6 (47)
4 + 3 = 7 (54)

The expressions allow for some additional functions to be used. Notably the randint(max) and rand() functions for genrating random numbers:

$ run 10 --def r "randint(100)" --format "{r}" -s ,
51,0,55,50,56,43,20,5,51,90

Note

The expressions are evaluated using the simpleeval module. Read the docs to see, what expressions are possible. In general, the basic arithmetic operators (+, -, *, /, *, //) are supported.

In version 0.4.3 the --filter option was added to filter out some values from the run. The option requires an expression similar to --def that evaluates to a boolean value. Any iteration that evaluates to False will be omitted from the run.

$ run 100 --filter "{}%3==0 and {}%5==0"
15
30
45
60
75
90

Examples

Generating a CSV file with a lists of decimal, binary and hexadecimal numbers:

$ echo "dec,bin,oct,hex" > hostnames.csv
$ run 0 255 -f "{0:2},{0:08b},{0:02o},{0:02X}" >> numbers.csv

Generating a list of computers in a network with hostnames and IP.

$ echo "room,hostname,ip" > hostnames.csv
$ run 4 --also 1 24 1 --also 1 16 1 -f "{0}{1:02},r{0}{1:02}-{2:02},18.45.{1}{0}.{2}" >> hostnames.csv