title: Various iterations of snakefile give the same error
body: <p>I am trying to use snakemake for a bioinformatics pipeline. To test it, I made the following snakefile. </p>
  
  <p>I have a directory with various fastq.gz files (e.g. K1_R1.fastq.gz, K1_R2.fastq.gz, K2_R1.fastq.gz etc) and I am running fastqc on them. </p>
  
  <pre><code>SAMPLES = [ "K1", "K2", "W1", "W2" ]
  REPLICATE = ['R1', 'R2']
  
  PathtoWD = '/home/hbanduk/scratch/working_projects_2020/'
  
  rule fastqc:
      input:
          "expand(PathtoWD + "/raw_data/{sample}_{replicate}.fastq.gz", sample=SAMPLES, replicate=REPLICATE)"
      output:
           PathtoWD + "/fastqc_raw_reads/{sample}_{replicate}_fastqc.zip",
           PathtoWD + "/fastqc_raw_reads/{sample}_{replicate}_fastqc.html"
      shell:
          "fastqc {input} -o /home/hbanduk/scratch/working_projects_2020/fastqc_raw_reads"
  </code></pre>
  
  <p>when I run, </p>
  
  <pre><code>snakemake -np snakefile
  </code></pre>
  
  <p>I get the following error:</p>
  
  <pre><code>SyntaxError in line 9 of 
  /scratch/hbanduk/working_projects_2020/Snakefile:
  invalid syntax
  </code></pre>
  
  <p>I have tried many permutations of this file but I keep getting the same error (othertimes for other lines). </p>
  
  <p>Any input will be greatly appreciated. </p>