code: def qfrom(ctx, q=None, m=None, k=None, tau=None, qbar=None):
      r"""
      Returns the elliptic nome `q`, given any of `q, m, k, \tau, \bar{q}`::
  
          >>> from mpmath import *
          >>> mp.dps = 25; mp.pretty = True
          >>> qfrom(q=0.25)
          0.25
          >>> qfrom(m=mfrom(q=0.25))
          0.25
          >>> qfrom(k=kfrom(q=0.25))
          0.25
          >>> qfrom(tau=taufrom(q=0.25))
          (0.25 + 0.0j)
          >>> qfrom(qbar=qbarfrom(q=0.25))
          0.25
  
      """
      if q is not None:
          return ctx.convert(q)
      if m is not None:
          return nome(ctx, m)
      if k is not None:
          return nome(ctx, ctx.convert(k) ** 2)
      if tau is not None:
          return ctx.expjpi(tau)
      if qbar is not None:
          return ctx.sqrt(qbar)
  
imports: from .functions import defun, defun_wrapped
label_desc: Use image node_id 3 for calling a global function with example usage: qfrom(ctx, q, m, k, tau, qbar) and returns: ctx, nome, nome, ctx, ctx