Question

我在 snakemake 中使用以下配置文件格式进行一些测序分析练习（我有大量样本，每个样本包含2个fastq文件：

samples:
Sample1_XY:
    - fastq_files/SRR4356728_1.fastq.gz
    - fastq_files/SRR4356728_2.fastq.gz
Sample2_AB:
    - fastq_files/SRR6257171_1.fastq.gz
    - fastq_files/SRR6257171_2.fastq.gz

我在管道的开头使用以下规则来运行fastqc并对齐fastqc文件：

import os
# read config info into this namespace
configfile: "config.yaml"

rule all:
    input:
    expand("FastQC/{sample}_fastqc.zip", sample=config["samples"]),
    expand("bam_files/{sample}.bam", sample=config["samples"]),
    "FastQC/fastq_multiqc.html"

rule fastqc:
    input:
        sample=lambda wildcards: config['samples'][wildcards.sample]
    output:
        # Output needs to end in '_fastqc.html' for multiqc to work
        html="FastQC/{sample}_fastqc.html",
        zip="FastQC/{sample}_fastqc.zip"
    params: ""
        wrapper:
        "0.21.0/bio/fastqc"

rule bowtie2:
    input:
         sample=lambda wildcards: config['samples'][wildcards.sample]
    output:
         "bam_files/{sample}.bam"
    log:
         "logs/bowtie2/{sample}.txt"
    params:
         index=config["index"],  # prefix of reference genome index (built with bowtie2-build),
    extra=""
         threads: 8
    wrapper:
         "0.21.0/bio/bowtie2/align"

 rule multiqc_fastq:
    input:
         expand("FastQC/{sample}_fastqc.html", sample=config["samples"])
    output:
         "FastQC/fastq_multiqc.html"
    params:
    log:
         "logs/multiqc.log"
    wrapper:
         "0.21.0/bio/multiqc"

我的问题在于fastqc规则。

目前fastqc规则和bowtie2规则都创建了一个使用两个输入SRRXXXXXXX_1.fastq.gz和SRRXXXXXXX_2.fastq.gz生成的输出文件。

我需要fastq规则来生成两个文件，每个fastq.gz文件都有一个单独的文件，但我不确定如何从fastqc规则输入语句正确索引配置文件，或者如何组合expand和wildcards命令来解决这个问题。我可以通过在输入语句的末尾添加[0]或[1]来获取单个fastq文件，但不能单独/单独运行。

我一直在努力寻找正确的索引格式来分别访问每个文件。当前格式是我管理的唯一一种允许snakemake -np生成作业列表的格式。

任何提示都将不胜感激。

Answer 1

每个样本看起来都有两个fastq文件，它们的格式为***_1.fastq.gz和***_2.fastq.gz。在这种情况下，下面的配置和代码将起作用。

config.yaml：

samples:
    Sample_A: fastq_files/SRR4356728
    Sample_B: fastq_files/SRR6257171

Snakefile：

# read config info into this namespace
configfile: "config.yaml"
print (config['samples'])

rule all:
    input:
        expand("FastQC/{sample}_{num}_fastqc.zip", sample=config["samples"], num=['1', '2']),
        expand("bam_files/{sample}.bam", sample=config["samples"]),
        "FastQC/fastq_multiqc.html"

rule fastqc:
    input:
        sample=lambda wildcards: f"{config['samples'][wildcards.sample]}_{wildcards.num}.fastq.gz"
    output:
        # Output needs to end in '_fastqc.html' for multiqc to work
        html="FastQC/{sample}_{num}_fastqc.html",
        zip="FastQC/{sample}_{num}_fastqc.zip"
    wrapper:
        "0.21.0/bio/fastqc"

rule bowtie2:
    input:
         sample=lambda wildcards: expand(f"{config['samples'][wildcards.sample]}_{{num}}.fastq.gz", num=[1,2])
    output:
         "bam_files/{sample}.bam"
    wrapper:
         "0.21.0/bio/bowtie2/align"

rule multiqc_fastq:
    input:
        expand("FastQC/{sample}_{num}_fastqc.html", sample=config["samples"], num=['1', '2'])
    output:
        "FastQC/fastq_multiqc.html"
    wrapper:
        "0.21.0/bio/multiqc"

Snakemake：如何有效地使用配置文件

1 个答案: