帶有awk和管道的Python子進程

Question

我的Python腳本中有以下語句：

year = '1966'
file = 'test.txt'
cmd = "awk '{FS="|"}{if ($2 == %s) print $1}' %s | sort -n | uniq | wc" % (year, file)
bla = run_command(cmd)

其中fun_command()是函數：

def run_command(command):                                     
  process = subprocess.Popen([sys.executable, command], shell=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
  retcode = process.wait()
  if retcode != 0:
    raise Exception, "Problem running command: " + command
  stdout, stderr = process.communicate()
  return stdout

產生以下輸出：

TypeError: unsupported operand type(s) for |: 'str' and 'str'

任何想法有什么問題嗎？

Answer 1

"awk '{FS="|"}{if ($2 == %s) print $1}' %s | sort -n | uniq | wc"
在這里，您需要轉義內部的"|"

"awk '{FS=\\"|\\"}{if ($2 == %s) print $1}' %s | sort -n | uniq | wc"

Answer 2

sys.executable是當前正在運行的Python解釋器，因此您嘗試將shell代碼作為Python代碼執行。 只需使用

def run_command(command):                                     
  process = subprocess.Popen(command, shell=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
  retcode = process.wait()
  if retcode != 0:
    raise Exception, "Problem running command: " + command
  stdout, stderr = process.communicate()
  return stdout