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Title: Only print `make venv` message when needed. by ezio-melotti · Pull Request #867 · python/devguide · GitHub

Open Graph Title: Only print `make venv` message when needed. by ezio-melotti · Pull Request #867 · python/devguide

X Title: Only print `make venv` message when needed. by ezio-melotti · Pull Request #867 · python/devguide

Description: When make venv is called if the venv doesn't exist, it creates it and announce its creation if it does, it says it exists and suggests make clean-venv This was added in #856, but because of this change, all other targets that have the venv target as a dependency now print the message saying that the venv exist. If venv is removed from the . PHONY list it doesn't get reevaluated and doesn't print the message, but this also applies when it's invoked directly, making the message that suggests make clean-venv useless since it's never printed. I wrestled with Makefile for a while, and this PR is the best I came up with. It's intelligible, but has some repetition. I tried to get rid of the repetition by creating a Makefile function: define create-venv = $(PYTHON) -m venv $(VENVDIR) $(VENVDIR)/bin/python3 -m pip install --upgrade pip $(VENVDIR)/bin/python3 -m pip install -r requirements.txt endef but I couldn't find a way to call it from the other target, since they use a bash if/else that can't be used to call makefile functions. Another option is to create a target instead of the function, and call it with make target: create-venv: $(PYTHON) -m venv $(VENVDIR) $(VENVDIR)/bin/python3 -m pip install --upgrade pip $(VENVDIR)/bin/python3 -m pip install -r requirements.txt @echo "The venv has been created in the $(VENVDIR) directory" venv: @if [ -d $(VENVDIR) ] ; then \ echo "venv already exists."; \ echo "To recreate it, remove it first with \`make clean-venv'."; \ else \ make create-venv; \ fi ensure-venv: @if [ ! -d $(VENVDIR) ] ; then \ make create-venv; \ fi this works, but it launches another instance of make and prints some extra messages like make[1]: Entering/Leaving directory '/home/user/devguide' -- not very elegant. There are other solutions that I explored, including conditional functions or conditional syntax. There are also other ways of detecting dirs and acting upon their presence/absence, but the intelligibility of all these solutions goes downhill pretty quickly. So the options are: Merge the current PR, with some duplication Add the create-venv target with nested make calls Find a solution that removes the duplication without looking like bad ASCII-art Remove the if/else from the venv target, document make clean-venv, and hope people figure it out by reading the help

Open Graph Description: When make venv is called if the venv doesn't exist, it creates it and announce its creation if it does, it says it exists and suggests make clean-venv This was added in #856, but because of t...

X Description: When make venv is called if the venv doesn't exist, it creates it and announce its creation if it does, it says it exists and suggests make clean-venv This was added in #856, but because ...

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