(expr, *vars, **kwargs)
return expr
A non-greedy collection of terms with similar number coefficients in
    an Add expr. If ``vars`` is given then only those constants will be
    targeted. Although any Number can also be targeted, if this is not
    desired set ``Numbers=False`` and no Float or Rational will be collected.

    Examples
    ========

    >>> from sympy import sqrt
    >>> from sympy.abc import a, s, x, y, z
    >>> from sympy.simplify.simplify import collect_const
    >>> collect_const(sqrt(3) + sqrt(3)*(1 + sqrt(2)))
    sqrt(3)*(sqrt(2) + 2)
    >>> collect_const(sqrt(3)*s + sqrt(7)*s + sqrt(3) + sqrt(7))
    (sqrt(3) + sqrt(7))*(s + 1)
    >>> s = sqrt(2) + 2
    >>> collect_const(sqrt(3)*s + sqrt(3) + sqrt(7)*s + sqrt(7))
    (sqrt(2) + 3)*(sqrt(3) + sqrt(7))
    >>> collect_const(sqrt(3)*s + sqrt(3) + sqrt(7)*s + sqrt(7), sqrt(3))
    sqrt(7) + sqrt(3)*(sqrt(2) + 3) + sqrt(7)*(sqrt(2) + 2)

    The collection is sign-sensitive, giving higher precedence to the
    unsigned values:

    >>> collect_const(x - y - z)
    x - (y + z)
    >>> collect_const(-y - z)
    -(y + z)
    >>> collect_const(2*x - 2*y - 2*z, 2)
    2*(x - y - z)
    >>> collect_const(2*x - 2*y - 2*z, -2)
    2*x - 2*(y + z)

    See Also
    ========
    collect, collect_sqrt, rcollect
A non-greedy collection of terms with similar number coefficients in
    an Add expr. If ``vars`` is given then only those constants will be
    targeted. Although any Number can also be targeted, if this is not
    desired set ``Numbers=False`` and no Float or Rational will be collected.
A non - greedy collection of terms with similar number coefficients in an Add expr . If vars is given then only those constants will be targeted . Although any Number can also be targeted if this is not desired set Numbers = False and no Float or Rational will be collected .
def collect_const(expr, *vars, **kwargs):
    """A non-greedy collection of terms with similar number coefficients in
    an Add expr. If ``vars`` is given then only those constants will be
    targeted. Although any Number can also be targeted, if this is not
    desired set ``Numbers=False`` and no Float or Rational will be collected.

    Examples
    ========

    >>> from sympy import sqrt
    >>> from sympy.abc import a, s, x, y, z
    >>> from sympy.simplify.simplify import collect_const
    >>> collect_const(sqrt(3) + sqrt(3)*(1 + sqrt(2)))
    sqrt(3)*(sqrt(2) + 2)
    >>> collect_const(sqrt(3)*s + sqrt(7)*s + sqrt(3) + sqrt(7))
    (sqrt(3) + sqrt(7))*(s + 1)
    >>> s = sqrt(2) + 2
    >>> collect_const(sqrt(3)*s + sqrt(3) + sqrt(7)*s + sqrt(7))
    (sqrt(2) + 3)*(sqrt(3) + sqrt(7))
    >>> collect_const(sqrt(3)*s + sqrt(3) + sqrt(7)*s + sqrt(7), sqrt(3))
    sqrt(7) + sqrt(3)*(sqrt(2) + 3) + sqrt(7)*(sqrt(2) + 2)

    The collection is sign-sensitive, giving higher precedence to the
    unsigned values:

    >>> collect_const(x - y - z)
    x - (y + z)
    >>> collect_const(-y - z)
    -(y + z)
    >>> collect_const(2*x - 2*y - 2*z, 2)
    2*(x - y - z)
    >>> collect_const(2*x - 2*y - 2*z, -2)
    2*x - 2*(y + z)

    See Also
    ========
    collect, collect_sqrt, rcollect
    """
    if not expr.is_Add:
        return expr

    recurse = False
    Numbers = kwargs.get('Numbers', True)

    if not vars:
        recurse = True
        vars = set()
        for a in expr.args:
            for m in Mul.make_args(a):
                if m.is_number:
                    vars.add(m)
    else:
        vars = sympify(vars)
    if not Numbers:
        vars = [v for v in vars if not v.is_Number]

    vars = list(ordered(vars))
    for v in vars:
        terms = defaultdict(list)
        Fv = Factors(v)
        for m in Add.make_args(expr):
            f = Factors(m)
            q, r = f.div(Fv)
            if r.is_one:
                # only accept this as a true factor if
                # it didn't change an exponent from an Integer
                # to a non-Integer, e.g. 2/sqrt(2) -> sqrt(2)
                # -- we aren't looking for this sort of change
                fwas = f.factors.copy()
                fnow = q.factors
                if not any(k in fwas and fwas[k].is_Integer and not
                        fnow[k].is_Integer for k in fnow):
                    terms[v].append(q.as_expr())
                    continue
            terms[S.One].append(m)

        args = []
        hit = False
        uneval = False
        for k in ordered(terms):
            v = terms[k]
            if k is S.One:
                args.extend(v)
                continue

            if len(v) > 1:
                v = Add(*v)
                hit = True
                if recurse and v != expr:
                    vars.append(v)
            else:
                v = v[0]

            # be careful not to let uneval become True unless
            # it must be because it's going to be more expensive
            # to rebuild the expression as an unevaluated one
            if Numbers and k.is_Number and v.is_Add:
                args.append(_keep_coeff(k, v, sign=True))
                uneval = True
            else:
                args.append(k*v)

        if hit:
            if uneval:
                expr = _unevaluated_Add(*args)
            else:
                expr = Add(*args)
            if not expr.is_Add:
                break

    return expr
def collect_const ( expr , * vars , * * kwargs ) : if not expr . is_Add : return expr recurse = False Numbers = kwargs . get ( 'Numbers' , True ) if not vars : recurse = True vars = set ( ) for a in expr . args : for m in Mul . make_args ( a ) : if m . is_number : vars . add ( m ) else : vars = sympify ( vars ) if not Numbers : vars = [ v for v in vars if not v . is_Number ] vars = list ( ordered ( vars ) ) for v in vars : terms = defaultdict ( list ) Fv = Factors ( v ) for m in Add . make_args ( expr ) : f = Factors ( m ) q , r = f . div ( Fv ) if r . is_one : # only accept this as a true factor if # it didn't change an exponent from an Integer # to a non-Integer, e.g. 2/sqrt(2) -> sqrt(2) # -- we aren't looking for this sort of change fwas = f . factors . copy ( ) fnow = q . factors if not any ( k in fwas and fwas [ k ] . is_Integer and not fnow [ k ] . is_Integer for k in fnow ) : terms [ v ] . append ( q . as_expr ( ) ) continue terms [ S . One ] . append ( m ) args = [ ] hit = False uneval = False for k in ordered ( terms ) : v = terms [ k ] if k is S . One : args . extend ( v ) continue if len ( v ) > 1 : v = Add ( * v ) hit = True if recurse and v != expr : vars . append ( v ) else : v = v [ 0 ] # be careful not to let uneval become True unless # it must be because it's going to be more expensive # to rebuild the expression as an unevaluated one if Numbers and k . is_Number and v . is_Add : args . append ( _keep_coeff ( k , v , sign = True ) ) uneval = True else : args . append ( k * v ) if hit : if uneval : expr = _unevaluated_Add ( * args ) else : expr = Add ( * args ) if not expr . is_Add : break return expr