Using Popen with multiple args and piping the output to display the actual error message

Since subprocess.check_call shouldn't have stdout and stderr pipes, you should use Popeninstead.

See the subprocess documentation especially check_call and for Popen.

import subprocess

eplus_path = '/Applications/EnergyPlus-8-6-0/energyplus'
eplus_file = '5ZoneAirCooled.idf'
weather_file = 'USA_CO_Golden-NREL.724666_TMY3.epw'

df = subprocess.Popen([eplus_path, "-w", weather_file, eplus_file], stdout=subprocess.PIPE)        
output, err = df.communicate()
print(output.decode('utf-8'))
if not err is None:
    print(err.decode('utf-8'))

In a case where it goes well, I'll see something that starts with:

EnergyPlus Starting
EnergyPlus, Version 8.6.0-198c6a3cff, YMD=2017.01.17 23:46
Processing Data Dictionary
Processing Input File
... etc

In a case where for example I don't have the right idf file in my folder:

ERROR: Could not find input data file: /Users/julien/Software/RunningEPlusFromPython/2ZoneAirCooled.idf.
Type 'energyplus --help' for usage.

Shlex as helper to parse a command

Note that the subprocess calls expects a list of arguments. Using shlex to decompose a command line (that you can try directly in a terminal/cmd prompt) can be useful:

In [1]:
import shlex
command_line = '{eplus_path} -w {weather_file} {eplus_file}'.format(eplus_path= eplus_path, weather_file=weather_file, eplus_file=eplus_file)
print(command_line)

Out [1]:
/Applications/EnergyPlus-8-6-0/energyplus -w USA_CO_Golden-NREL.724666_TMY3.epw 5ZoneAirCooled.idf

In [2]: shlex.split(command_line)
Out[2]: ['/Applications/EnergyPlus-8-6-0/energyplus',
         '-w',
         'USA_CO_Golden-NREL.724666_TMY3.epw',
         '5ZoneAirCooled.idf']

Seeing the EnergyPlus simulation output in real time as the simulation runs

If you need to do this, here's how:

import subprocess
# If python 2.7: `from __future__ import print_function`

popen = subprocess.Popen([eplus_path, "-w", weather_file, eplus_file],
                         stdout=subprocess.PIPE, universal_newlines=True)

# Might need to use `#for stdout_line in iter(popen.stdout.readline, ""):` instead in python 2.7
for stdout_line in popen.stdout:
    print(stdout_line)

popen.stdout.close()
return_code = popen.wait()

if return_code:
    raise subprocess.CalledProcessError(return_code, popen.args)

Since subprocess.check_call shouldn't have stdout and stderr pipes, you should use Popeninstead.

See the subprocess documentation especially check_call and for Popen.

import subprocess

eplus_path = '/Applications/EnergyPlus-8-6-0/energyplus'
eplus_file = '5ZoneAirCooled.idf'
weather_file = 'USA_CO_Golden-NREL.724666_TMY3.epw'

df = subprocess.Popen([eplus_path, "-w", weather_file, eplus_file], stdout=subprocess.PIPE)        
output, err = df.communicate()
print(output.decode('utf-8'))
if not err is None:
    print(err.decode('utf-8'))

In a case where it goes well, I'll see something that starts with:

EnergyPlus Starting
EnergyPlus, Version 8.6.0-198c6a3cff, YMD=2017.01.17 23:46
Processing Data Dictionary
Processing Input File
... etc

In a case where for example I don't have the right idf file in my folder:

ERROR: Could not find input data file: /Users/julien/Software/RunningEPlusFromPython/2ZoneAirCooled.idf.
Type 'energyplus --help' for usage.

Note that the subprocess calls expects a list of arguments. Using shlex to decompose a command line (that you can try directly in a terminal/cmd prompt) can be useful:

In [1]:
import shlex
command_line = '{eplus_path} -w {weather_file} {eplus_file}'.format(eplus_path= eplus_path, weather_file=weather_file, eplus_file=eplus_file)
print(command_line)

Out [1]:
/Applications/EnergyPlus-8-6-0/energyplus -w USA_CO_Golden-NREL.724666_TMY3.epw 5ZoneAirCooled.idf

In [2]: shlex.split(command_line)
Out[2]: ['/Applications/EnergyPlus-8-6-0/energyplus',
         '-w',
         'USA_CO_Golden-NREL.724666_TMY3.epw',
         '5ZoneAirCooled.idf']

import subprocess
# If python 2.7: `from __future__ import print_function`

popen = subprocess.Popen([eplus_path, "-w", weather_file, eplus_file],
                         stdout=subprocess.PIPE, universal_newlines=True)

# Might need to use `#for stdout_line in iter(popen.stdout.readline, ""):` instead in python 2.7
for stdout_line in popen.stdout:
    print(stdout_line)

popen.stdout.close()
return_code = popen.wait()

if return_code:
    raise subprocess.CalledProcessError(return_code, popen.args)

Since subprocess.check_call shouldn't have stdout and stderr pipes, you should use Popeninstead.

See the subprocess documentation especially check_call and for Popen.

import subprocess

eplus_path = '/Applications/EnergyPlus-8-6-0/energyplus'
eplus_file = '5ZoneAirCooled.idf'
weather_file = 'USA_CO_Golden-NREL.724666_TMY3.epw'

df = subprocess.Popen([eplus_path, "-w", weather_file, eplus_file], stdout=subprocess.PIPE)        
output, err = df.communicate()
print(output.decode('utf-8'))
if not err is None:
    print(err.decode('utf-8'))

In a case where it goes well, I'll see something that starts with:

EnergyPlus Starting
EnergyPlus, Version 8.6.0-198c6a3cff, YMD=2017.01.17 23:46
Processing Data Dictionary
Processing Input File
... etc

In a case where for example I don't have the right idf file in my folder:

ERROR: Could not find input data file: /Users/julien/Software/RunningEPlusFromPython/2ZoneAirCooled.idf.
Type 'energyplus --help' for usage.

In [1]:
import shlex
command_line = '{eplus_path} -w {weather_file} {eplus_file}'.format(eplus_path= eplus_path, weather_file=weather_file, eplus_file=eplus_file)
print(command_line)

Out [1]:
/Applications/EnergyPlus-8-6-0/energyplus -w USA_CO_Golden-NREL.724666_TMY3.epw 5ZoneAirCooled.idf

In [2]: shlex.split(command_line)
Out[2]: ['/Applications/EnergyPlus-8-6-0/energyplus',
         '-w',
         'USA_CO_Golden-NREL.724666_TMY3.epw',
         '5ZoneAirCooled.idf']

Since subprocess.check_call shouldn't have stdout and stderr pipes, you should use Popeninstead.

See the instead (see subprocess documentation especially check_calldocumentation and for Popen.)

import subprocess

eplus_path = '/Applications/EnergyPlus-8-6-0/energyplus'
eplus_file = '5ZoneAirCooled.idf'
weather_file = 'USA_CO_Golden-NREL.724666_TMY3.epw'

df = subprocess.Popen([eplus_path, "-w", weather_file, eplus_file], stdout=subprocess.PIPE)        
output, err = df.communicate()
print(output.decode('utf-8'))
if not err is None:
    print(err.decode('utf-8'))

In a case where it goes well, I'll see something that starts with:

EnergyPlus Starting
EnergyPlus, Version 8.6.0-198c6a3cff, YMD=2017.01.17 23:46
Processing Data Dictionary
Processing Input File
... etc

In a case where for example I don't have the right idf file in my folder:

ERROR: Could not find input data file: /Users/julien/Software/RunningEPlusFromPython/2ZoneAirCooled.idf.
Type 'energyplus --help' for usage.

Since subprocess.check_call shouldn't have stdout and stderr pipes, piped, you should use Popeninstead (see subprocess documentation)instead.

import subprocess
subprocess  
eplus_path = '/Applications/EnergyPlus-8-6-0/energyplus'
eplus_file = '5ZoneAirCooled.idf'
weather_file = 'USA_CO_Golden-NREL.724666_TMY3.epw'
'USA_CO_Golden-NREL.724666_TMY3.epw'  
df = subprocess.Popen([eplus_path, "-w", weather_file, eplus_file], stdout=subprocess.PIPE)  

output, err = df.communicate()
print(output.decode('utf-8'))
if not err is None:
    print(err.decode('utf-8'))

EnergyPlus Starting
EnergyPlus, Version 8.6.0-198c6a3cff, YMD=2017.01.17 23:46
Processing Data Dictionary
Processing Input File
... etc

ERROR: Could not find input data file: /Users/julien/Software/RunningEPlusFromPython/2ZoneAirCooled.idf.
Type 'energyplus --help' for usage.