How to get exit code when using Python subprocess communicate method

Question

How do I retrieve the exit code when using Python s subprocess module and the communicate   method   Relevant code   import subprocess as sp data   sp Popen openRTSP   opts split    stdout sp PIPE  communicate   0    Should I be doing this another way

User · Answer

You should first make sure that the process has completed running and the return code has been read out using the  wait method  This will return the code  If you want access to it later  it s stored as  returncode in the Popen object

User · Answer

Use process wait   after you call process communicate     For example  import subprocess  process   subprocess Popen   ipconfig     all    stderr subprocess PIPE  stdout subprocess PIPE  stdout  stderr   process communicate   exit code   process wait   print stdout  stderr  exit code

User · Answer

poll   will update the return code   Try  child   sp Popen openRTSP   opts split    stdout sp PIPE  returnCode   child poll     In addition  after  poll   is called the return code is available in the object as child returncode

User · Answer

Popen communicate will set the returncode attribute when it s done     Here s the relevant documentation section   Popen returncode    The child return code  set by poll   and wait    and indirectly by communicate        A None value indicates that the process hasn   t terminated yet     A negative value -N indicates that the child was terminated by signal N  Unix only     So you can just do  I didn t test it but it should work    import subprocess as sp child   sp Popen openRTSP   opts split    stdout sp PIPE  streamdata   child communicate   0  rc   child returncode         This happens because of the way it s implemented  after setting up threads to read the child s streams  it just calls wait

User · Answer

This worked for me  It also prints the output returned by the child process  child   subprocess Popen serial script cmd  shell True  stdout subprocess PIPE  stderr subprocess STDOUT      retValRunJobsSerialScript   0     for line in child stdout readlines            child wait           print line                retValRunJobsSerialScript  child returncode

User · Answer

exitcode   data wait    The child process will be blocked If it writes to standard output error  and or reads from standard input  and there are no peers

User · Answer

Please see the comments  Code  import subprocess   class MyLibrary object        def execute self  cmd           return subprocess Popen cmd  stdout subprocess PIPE  stderr subprocess STDOUT  universal newlines True              def list self           command     quot ping quot    quot google com quot           sp   self execute command          status   sp wait      will wait for sp to finish         out  err   sp communicate           print out          return status   0 is success else error   test   MyLibrary    print test list     Output  C  Users shita Documents Tech Python gt python t5 py  Pinging google com  142 250 64 78  with 32 bytes of data  Reply from 142 250 64 78  bytes 32 time 108ms TTL 116 Reply from 142 250 64 78  bytes 32 time 224ms TTL 116 Reply from 142 250 64 78  bytes 32 time 84ms TTL 116 Reply from 142 250 64 78  bytes 32 time 139ms TTL 116  Ping statistics for 142 250 64 78      Packets  Sent   4  Received   4  Lost   0  0  loss   Approximate round trip times in milli-seconds      Minimum   84ms  Maximum   224ms  Average   138ms  0

[python] How to get exit code when using Python subprocess communicate method?

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