如果将约定
pram_axdnull理解
"-"为：“从stdin中读取”，则可以：
p = Popen(["pram_axdnull", str(kmer), input_filename, "-"], stdin=PIPE, stdout=PIPE)output = p.communicate(generate_kmers(3))[0]
如果输入是由外部过程生成的：
kmer_proc = Popen(["generate_kmers", str(kmer)], stdout=PIPE)p = Popen(["pram_axdnull", str(kmer), input_filename, "-"], stdin=kmer_proc.stdout, stdout=PIPE)kmer_proc.stdout.close()output = p.communicate()[0]
如果
pram_axdnull不 明白
"-"的约定：
import osimport tempfilefrom subprocess import check_outputwith tempfile.NamedTemporaryFile() as file: file.write(generate_kmers(3)) file.delete = Falsetry: p = Popen(["pram_axdnull", str(kmer), input_filename, file.name], stdout=PIPE) output = p.communicate()[0] # or # output = check_output(["pram_axdnull", str(kmer), input_filename, file.name])finally: os.remove(file.name)
要使用外部过程生成临时文件：
from subprocess import check_callwith tempfile.NamedTemporaryFile() as file: check_call(["generate_kmers", str(kmer)], stdout=file) file.delete = False
为了避免等待所有kmers生成，即同时写入/读取kmers，可以
os.mkfifo()在Unix上使用（由@cdarke建议）：
import osimport shutilimport tempfilefrom contextlib import contextmanagerfrom subprocess import Popen, PIPE@contextmanagerdef named_pipe(): dirname = tempfile.mkdtemp() try: path = os.path.join(dirname, 'named_pipe') os.mkfifo(path) yield path finally: shutil.rmtree(dirname)with named_pipe() as path: p = Popen(["pram_axdnull", str(kmer), input_filename, path], stdout=PIPE) # read from path with open(path, 'wb') as wpipe: kmer_proc = Popen(["generate_kmers", str(kmer)], stdout=wpipe) # write to path output = p.communicate()[0] kmer_proc.wait()
