Error Accessing Values in Snakemake Config File

Question

[Sonny]

Hello,

I am trying to load some files from a config file in snakemake. I'm using snakemake 7.22 on MacOS Monterey with M1 chip. My config file is:

files:
  A: file1.txt
  B: file2.txt

My Snakemake file is:

configfile: "config.yaml"

rule all:
    input:
        expand("{file}", file=config["files"])
    output:
        "summary.txt"
    shell:
        "ls {input} > {output}"

When running with:

snakemake --cores 1

I get:

MissingInputException in rule all in file projects/data-science/test/Snakefile, line 3:
Missing input files for rule all:
    output: summary.txt
    affected files:
        B
        A

The keys of the config dictionary appear to be used instead of the values. I was working based on the example in the Snakemake tutorial:

https://snakemake.readthedocs.io/en/v7.22.0/tutorial/advanced.html#step-2-config-files

I can't see how my example differs from the example in the docs. I should point out that I am aware that the problem can be solved by changing the config file to:

files:
  - file1.txt
  - file2.txt

However, I'm curious why the dictionary approach is not working for me. Any help would be appreciated.

[size_t]

in config.yaml， file A and B must be exists,

[Sonny]

Thanks, file1.txt and file2.txt exist. In the linked example in the tutorial (https://snakemake.readthedocs.io/en/v7.22.0/tutorial/advanced.html#step-2-config-files), it appears that the value of the dictionary is used instead of the keys. Am I missing something with the difference between my example and the example in the docs?

[size_t]

your snakemake file change like this: