I'm using Python to automate some work I'm doing in machine learning. The machine learning tool I'm using is Vowpal Wabbit and I usually run it from terminal.
I'm able to use Python's call(vw\_command,shell=True) to run Vowpal Wabbit, but I also want to capture VW's entire shell output.
This is what I tried:

```
output =check_output(vw_command, shell=True)

```

This is what I see in my Python IDE:

```
creating quadratic features for pairs: hh hb hp hr  final_regressor = model_vw.vw Num weight bits = 28 learning rate = 0.7 initial_t = 0 power_t = 0.5 decay_learning_rate = 1 creating cache_file = fold1.vw.cache Reading datafile = fold1.vw num sources = 1 average    since         example     example  current  current  current loss      last          counter      weight    label  predict features
0.693147   0.693147            1         1.0  -1.0000   0.0000     1209
0.615108   0.537070            2         2.0  -1.0000  -0.3411     1217
0.527696   0.440284            4         4.0  -1.0000  -0.5287     1217
0.474677   0.421658            8         8.0  -1.0000  -0.9651     1201
0.363831   0.252986           16        16.0  -1.0000  -1.2778     1217
0.259342   0.154852           32        32.0  -1.0000  -2.1993     1209
0.170503   0.081664           64        64.0  -1.0000  -2.5598     1217
0.106260   0.042017          128       128.0  -1.0000  -2.8044     1217
0.083359   0.060457          256       256.0  -1.0000  -8.8870     1217
0.056569   0.029780          512       512.0  -1.0000  -4.4179     1209
0.044556   0.032542         1024      1024.0  -1.0000  -4.0888     1209
0.036272   0.027989         2048      2048.0  -1.0000  -5.3605     1217
0.033533   0.030794         4096      4096.0  -1.0000  -5.7477     1199
0.026593   0.019653         8192      8192.0  -1.0000  -9.1520     1194
0.019215   0.011837        16384     16384.0  -1.0000 -13.8832     1209
0.014147   0.009079        32768     32768.0  -1.0000  -9.5163     1209
0.012523   0.010898        65536     65536.0  -1.0000 -17.4003     1209
0.009721   0.006920       131072    131072.0  -1.0000 -13.1049     1217
0.007038   0.004355       262144    262144.0  -1.0000 -10.1183     1209
0.005340   0.003642       524288    524288.0  -1.0000 -10.7823     1203
0.003909   0.002478      1048576   1048576.0  -1.0000  -9.5997     1209
0.002318   0.000727      2097152   2097152.0  -1.0000 -22.7368     1217

finished run
number of examples per pass = 425000
passes used = 1
weighted example sum = 425000
weighted label sum = -419716
average loss = 236.561
best constant = -0.987572
total feature number = 514554601

```

But when I look at the variable output it is an empty string ''.
How do I capture the entire shell output?