Issue
=====

Using [GeoPandas](https://geopandas.org/):

this:

```
(...)
t_srs = 4326
gdf.set_geometry('geom', crs={'init': u'epsg:'+str(t_srs)}, inplace=True)

```

or this:

```
(...)
gpd.read_postgis(sql_string, conn, geom_col='geom', crs={'init': u'epsg:'+str(t_srs)})

```

raise a warning today:

```
/usr/local/lib/python3.6/dist-packages/pyproj/crs.py:77:     
FutureWarning: 
    '+init=<authority>:<code>' syntax is deprecated.     
    '<authority>:<code>'  is the preferred initialization method.
  return _prepare_from_string(" ".join(pjargs))

```

and if I remove the `'init'` key of the `crs` [dictionary](https://docs.python.org/3/tutorial/datastructures.html#dictionaries), I got this error;

`CRSError: Invalid CRS input: {'epsg:4326'}`

And if, by chance, I try with `{'epsg':'4326'}` or `{'epsg':4326}` ; these errors are respectively raised: 

```
CRSError: Invalid projection: {"epsg": "4326"}: (Internal Proj Error: proj_create: Missing "type" key)

```

and:

```
CRSError: Invalid projection: {"epsg": 4326}: (Internal Proj Error: proj_create: Missing "type" key)

```

Question
========

Is it already possible to write some [GeoPandas](https://geopandas.org/) code that corresponds to the new\* [pyproj](http://pyproj4.github.io/pyproj/latest/) projection initialization method using `<authority>:<code>` instead of `+init=<authority>:<code>` ?

* <https://pyproj4.github.io/pyproj/stable/gotchas.html>