update codestyle-PEP8

observation_sim/psf/PSFGauss.py

@@ -50,7 +50,7 @@ class PSFGauss(PSFModel):
 
         Return: the flux ratio
         """
-        if pscale == None:
+        if pscale is None:
             pscale = self.pix_size
         gaussx = galsim.Gaussian(flux=1.0, sigma=sig)
         gaussImg = gaussx.drawImage(scale=pscale, method='no_pixel')
@@ -68,7 +68,7 @@ class PSFGauss(PSFModel):
 
         return the fwhm in arcsec
         """
-        if pscale == None:
+        if pscale is None:
             pscale = self.pix_size
         err = 1.0e-3
         nxx = 100
@@ -123,3 +123,4 @@ class PSFGauss(PSFModel):
         # return ell, beta, qr
         PSFshear = galsim.Shear(e=ell, beta=beta*galsim.radians)
         return self.psf.shear(PSFshear), PSFshear
+