https://bioinformaticsonline.com/snippets/view/44438/python-script-to-convert-multi-line-fasta-to-single-line-fasta? https://bioinformaticsonline.com/snippets/view/44438/python-script-to-convert-multi-line-fasta-to-single-line-fasta Wed, 31 Jan 2024 00:37:15 -0600 https://bioinformaticsonline.com/snippets/view/44438/python-script-to-convert-multi-line-fasta-to-single-line-fasta def multi_to_single_line_fasta(input_filename, output_filename): try: with open(input_filename, 'r') as input_file: with open(output_filename, 'w') as output_file: current_sequence = "" for line in input_file: if line.startswith('>'): # If a header line, write the previous sequence and then the new header if current_sequence: output_file.write(current_sequence + '\n') output_file.write(line.strip() + '\n') current_sequence = "" else: # If a sequence line, concatenate to the current sequence current_sequence += line.strip() # Write the last sequence if current_sequence: output_file.write(current_sequence + '\n') print(f"Successfully converted {input_filename} to {output_filename} in single-line FASTA format.") except FileNotFoundError: print(f"Error: File '{input_filename}' not found.") # Example usage: # multi_to_single_line_fasta('multi_line.fasta', 'single_line.fasta')]]> BioStar