Python 忽略具有多个模式匹配的行

Question

I have a list as below:

Index1_list=['ATTACTCG','TCCGGAGA','CGCTCATT','GAGATTCC','ATTCAGAA']

What I want to do is to save lines if lines only have one of the list elements inside (not two different or three different)

>seq1
NNNNNNNNNNNNNNNNATTACTCGNNNNNNNNNNNGAGATTCCNNNNN
>seq2
NNNNNNNNNNNNNATTACTCGNNNNNNNNNN
>seq3
NNNNNNNNNNNNNGAGATTCCNNNNNNNNNNN

the output should be

>seq2
NNNNNNNNNNNNNATTACTCGNNNNNNNNNN
>seq3
NNNNNNNNNNNNNGAGATTCCNNNNNNNNNNN

I used the script below but have not been able to filter out reads with two different matches.

from Bio import SeqIO

Index1_list=['ATTACTCG','TCCGGAGA','CGCTCATT','GAGATTCC','ATTCAGAA']


with open('All.fastq','r') as R1:
    for record in SeqIO.parse(R1,'fasta'):
        for i in Index1_list:
            if i in record.seq:
                sequences = record.format('fasta')
                print(sequences)

Thank you.

Answer 1

You should be able to do what you want by checking how many elements from your list are in the desired string, like this:

from Bio import SeqIO

Index1_list=['ATTACTCG','TCCGGAGA','CGCTCATT','GAGATTCC','ATTCAGAA']


with open('All.fastq','r') as R1:
    for record in SeqIO.parse(R1,'fasta'):
        count = 0

        for i in Index1_list:
            if i in record.seq:
                count += 1

        if count == 1:
            sequences = record.format('fasta')
            print(sequences)