Makefile: Generate target from numeric sequence

Question

I am interested in downloading yearly data from some location on the internet. I have a python script GetYearData.py which does this, taking as a command-line argument the year and the output filename. I'd like to run this script on several years of data at once; I want to use Make so that if I change the start or end year I don't have to re-download all the data.

I can do this for a single year with a very simple Makefile:

data/YearData_2000.txt  :  GetYearData.py
  python $< --year 2000 --outfile $@

However, I'd like to do this a loop (or similar construction) so that, for each year in a sequence in bash I'd say YEARS=($(seq $(SYEAR) 1 $(EYEAR))) -- I pass --year $(Y) to my script and generate an appropriate target for --outfile?

Answer 1

Try something like:

SYEAR = 2000
EYEAR = 2017

YEARS := $(shell seq $(SYEAR) 1 $(EYEAR))

all: $(patsubst %,data/YearData_%.txt,$(YEARS))

data/YearData_%.txt : GetYearData.py
        python $< --year $* --outfile $@

You can override SYEAR and EYEAR on the make command line if you want.