write_data_segmentation_fault.py

import pytraj as pt
from pytraj.core.c_core import Command
from pytraj import CpptrajState

# data is DatasetGridFloat
data = pt.io.read_data('fav8.guv.O.1.ccp4',
                       options='name MyCcp4')[0]

state = CpptrajState()

# add DatasetGridFloat to CpptrajState's DataSetList
state.data.add(dtype=data.dtype, name=data.key)

# add data to DataSet
state.data[0].data = data.values
print(state)

data = state.data[0]
print(data.key, data.dtype, data.values[0])

# create cpptraj command
filename = 'test.ccp4'
options = ''
line = ' '.join(('writedata', filename, data.key, options))
# line is: writedata test.ccp4 MyCcp4

# dispatch
pt._verbose()
with Command() as cm:
    cm.dispatch(state, line)

I do see the output test.ccp4 but it's empty.