concatenate_data_sets change data label of input sacc's

[carlosggarcia]

If labels are passed to concatenate_data_sets, this will not only modify the label in the final sacc file, but also in the input ones.

Expected behavior: the original sacc's are left the same.

I guess the problem is with this line:

sacc/sacc/sacc.py

Line 1261 in e4c23bc

d = copy.copy(d)

; which is not copying everything but referring to the memory for some quantities of the sacc file.

This can be reproduced with this code (basically from test/test_sacc2.py)

import numpy as np
import sacc

s1 = sacc.Sacc()

# Tracer
z = np.arange(0., 1.0, 0.01)
nz = (z-0.5)**2/0.1**2
s1.add_tracer('NZ', 'source_0', z, nz)

for i in range(20):
    ee = 0.1 * i
    tracers = ('source_0', 'source_0')
    s1.add_data_point(sacc.standard_types.galaxy_shear_cl_ee,
                      tracers, ee, ell=10.0*i)

s2 = sacc.Sacc()

# Tracer
z = np.arange(0., 1.0, 0.01)
nz = (z-0.5)**2/0.1**2
s2.add_tracer('NZ', 'source_0', z, nz,
              quantity='galaxy_shear', spin=2)

for i in range(20):
    ee = 0.1 * i
    tracers = ('source_0', 'source_0')
    s2.add_data_point(sacc.standard_types.galaxy_shear_cl_ee,
                      tracers, ee, ell=10.0*i, label='xxx')


# Clash
s3 = sacc.concatenate_data_sets(s1, s2, labels=['1', '2'])

for i in range(20):
    # assert s2.data[i].get_tag('label') == 'xxx'
    print(s2.data[i].get_tag('label'))

for i in range(20):
    # assert s1.data[i].get_tag('label') is None
    print(s1.data[i].get_tag('label'))

[joezuntz]

One solution to this would be to add a __copy__ method somewhere, I think. Will need to think some more, but many thanks for spotting this.