Syntax error from list comprehension with a conditional

Question

I am using a library (pymatgen) in which a enum Orbital is defined. Each element can be defined as an OrbitalType. There are several flavors of orbital types which are defined by the letters s, p, d, and f. The following code works fine.

In [35]: myorbitals = []
In [36]: for orbital in Orbital:
   ....:     if orbital.orbital_type == OrbitalType.d:
   ....:         myorbitals.append(orbital)
   ....:       

In [37]: myorbitals
Out[37]:  [<Orbital.dxy: 4>,  <Orbital.dyz: 5>, 
<Orbital.dz2: 6>,  <Orbital.dxz: 7>,  <Orbital.dx2: 8>]

My question is, why do I get a syntax error when I attempt to do the same thing to construct myarray using a list comprehension?

In [38]: myarray = [orbital if orbital.orbital_type == OrbitalType.d for orbital in Orbital]

  File "<ipython-input-38-a770dfff8a02>", line 1
    myarray = [orbital if orbital.orbital_type == OrbitalType.d for orbital in Orbital]
                                                                  ^
SyntaxError: invalid syntax

Answer 1

正确的语法应为：

myarray = [orbital for orbital in Orbital if orbital.orbital_type == OrbitalType.d]