# Source code for pymatgen.io.abinit.variable

    import string
    import warnings
    import collections
    import numpy as np

    __all__ = [
        'InputVariable',
    ]

    _SPECIAL_DATASET_INDICES = (':', '+', '?')

    _DATASET_INDICES = ''.join(list(string.digits) + list(_SPECIAL_DATASET_INDICES))

    _INTERNAL_DATASET_INDICES = ('__s', '__i', '__a')

    _SPECIAL_CONVERSION = zip(_INTERNAL_DATASET_INDICES, _SPECIAL_DATASET_INDICES)

    _UNITS = {
        'bohr': 1.0,
        'angstrom': 1.8897261328856432,
        'hartree': 1.0,
        'Ha': 1.0,
        'eV': 0.03674932539796232,
    }

    class InputVariable(object):
        """
        An Abinit input variable.
        """
        def __init__(self, name, value, units='', valperline=3):

            self._name = name
            self.value = value
            self._units = units

            # Maximum number of values per line.
            self.valperline = valperline
            if name in ['bdgw']:
                self.valperline = 2

            if (is_iter(self.value) and isinstance(self.value[-1], str) and self.value[-1] in _UNITS):
                self.value = list(self.value)
                self._units = self.value.pop(-1)

        def get_value(self):
            """Return the value."""
            if self.units:
                return list(self.value) + [self.units]
            else:
                return self.value

        @property
        def name(self):
            return self._name

        @property
        def basename(self):
            """Return the name trimmed of any dataset index."""
            basename = self.name
            return basename.rstrip(_DATASET_INDICES)

        @property
        def dataset(self):
            """Return the dataset index in string form."""
            return self.name.split(self.basename)[-1]

        @property
        def units(self):
            """Return the units."""
            return self._units

        def __str__(self):
            """Declaration of the variable in the input file."""
            value = self.value
            if value is None or not str(value):
                return ''

            var = self.name
            line = ' ' + var

            # By default, do not impose a number of decimal points
            floatdecimal = 0

            # For some inputs, enforce number of decimal points...
            if any(inp in var for inp in ('xred', 'xcart', 'rprim', 'qpt', 'kpt')):
                floatdecimal = 16

            # ...but not for those
            if any(inp in var for inp in ('ngkpt', 'kptrlatt', 'ngqpt', 'ng2qpt')):
                floatdecimal = 0

            if isinstance(value, np.ndarray):
                n = 1
                for i in np.shape(value):
                    n *= i
                value = np.reshape(value, n)
                value = list(value)

            # values in lists
            if isinstance(value, (list, tuple)):

                # Reshape a list of lists into a single list
                if all(isinstance(v, (list, tuple)) for v in value):
                    line += self.format_list2d(value, floatdecimal)

                else:
                    line += self.format_list(value, floatdecimal)

            # scalar values
            else:
                line += ' ' + str(value)

            # Add units
            if self.units:
                line += ' ' + self.units

            return line

        def format_scalar(self, val, floatdecimal=0):
            """
            Format a single numerical value into a string
            with the appropriate number of decimal.
            """
            sval = str(val)
            if sval.lstrip('-').lstrip('+').isdigit() and floatdecimal == 0:
                return sval

            try:
                fval = float(val)
            except Exception:
                return sval

            if fval == 0 or (abs(fval) > 1e-3 and abs(fval) < 1e4):
                form = 'f'
                addlen = 5
            else:
                form = 'e'
                addlen = 8

            ndec = max(len(str(fval-int(fval)))-2, floatdecimal)
            ndec = min(ndec, 10)

            sval = '{v:>{l}.{p}{f}}'.format(v=fval, l=ndec+addlen, p=ndec, f=form)

            sval = sval.replace('e', 'd')

            return sval

        def format_list2d(self, values, floatdecimal=0):
            """Format a list of lists."""
            lvals = flatten(values)

            # Determine the representation
            if all(isinstance(v, int) for v in lvals):
                type_all = int
            else:
                try:
                    for v in lvals:
                        float(v)
                    type_all = float
                except Exception:
                    type_all = str

            # Determine the format
            width = max(len(str(s)) for s in lvals)
            if type_all == int:
                formatspec = '>{0}d'.format(width)
            elif type_all == str:
                formatspec = '>{0}'.format(width)
            else:

                # Number of decimal
                maxdec = max(len(str(f-int(f)))-2 for f in lvals)
                ndec = min(max(maxdec, floatdecimal), 10)

                if all(f == 0 or (abs(f) > 1e-3 and abs(f) < 1e4) for f in lvals):
                    formatspec = '>{w}.{p}f'.format(w=ndec+5, p=ndec)
                else:
                    formatspec = '>{w}.{p}e'.format(w=ndec+8, p=ndec)

            line = '\n'
            for L in values:
                for val in L:
                    line += ' {v:{f}}'.format(v=val, f=formatspec)
                line += '\n'

            return line.rstrip('\n')

        def format_list(self, values, floatdecimal=0):
            """
            Format a list of values into a string.
            The result might be spread among several lines.
            """
            line = ''

            # Format the line declaring the value
            for i, val in enumerate(values):
                line += ' ' + self.format_scalar(val, floatdecimal)
                if self.valperline is not None and (i+1) % self.valperline == 0:
                    line += '\n'

            # Add a carriage return in case of several lines
            if '\n' in line.rstrip('\n'):
                line = '\n' + line

            return line.rstrip('\n')

    def is_iter(obj):
        """Return True if the argument is list-like."""
        return hasattr(obj, '__iter__')

    def flatten(iterable):
        """Make an iterable flat, i.e. a 1d iterable object."""
        iterator = iter(iterable)
        array, stack = collections.deque(), collections.deque()
        while True:
            try:
                value = next(iterator)
            except StopIteration:
                if not stack:
                    return tuple(array)
                iterator = stack.pop()
            else:
                if not isinstance(value, str) \
                   and isinstance(value, collections.Iterable):
                    stack.append(iterator)
                    iterator = iter(value)
                else:
                    array.append(value)