Python WKT or Proj4 lookup package

I'd use the Python bindings for GDAL and OGR. If GDAL/OGR is installed on our machine, the pcs.csv file in gdal-data directory contains an extract of the EPSG Registry about projected coordinate reference systems, so we can filter this file to obtain the result. Suppose we are interested in zone 33, here's a quick and dirty solution:

from osgeo import ogr, osr

in_ds = ogr.GetDriverByName('CSV').Open('pcs.csv')
layer = in_ds.GetLayer()
zone = '33' #'33N'
layer.SetAttributeFilter("COORD_REF_SYS_NAME LIKE '%UTM zone {0}%'".format(zone))
for feature in layer:
    code = feature.GetField("COORD_REF_SYS_CODE")
    name = feature.GetField("COORD_REF_SYS_NAME")
    srs = osr.SpatialReference()
    srs.ImportFromEPSG(int(code))
    print 'EPSG:' + code + ' - ' + name
    print 'Proj4: ', srs.ExportToProj4()
    print 'WKT: ', srs.ExportToWkt()
    print

Note: we can refine the search choosing also the hemisphere (e.g. 33N) changing the value of the zone variable in the code.

This is an extract of the result:

EPSG:2078 - ELD79 / UTM zone 33N
Proj4:  +proj=utm +zone=33 +ellps=intl +towgs84=-115.8543,-99.0583,-152.4616,0,0,0,0 +units=m +no_defs 
WKT:  PROJCS["ELD79 / UTM zone 33N",GEOGCS["ELD79",DATUM["European_Libyan_Datum_1979",SPHEROID["International 1924",6378388,297,AUTHORITY["EPSG","7022"]],TOWGS84[-115.8543,-99.0583,-152.4616,0,0,0,0],AUTHORITY["EPSG","6159"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4159"]],PROJECTION["Transverse_Mercator"],PARAMETER["latitude_of_origin",0],PARAMETER["central_meridian",15],PARAMETER["scale_factor",0.9996],PARAMETER["false_easting",500000],PARAMETER["false_northing",0],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AXIS["Easting",EAST],AXIS["Northing",NORTH],AUTHORITY["EPSG","2078"]]

EPSG:2312 - Garoua / UTM zone 33N
Proj4:  +proj=utm +zone=33 +ellps=clrk80 +units=m +no_defs 
WKT:  PROJCS["Garoua / UTM zone 33N",GEOGCS["Garoua",DATUM["Garoua",SPHEROID["Clarke 1880 (RGS)",6378249.145,293.465,AUTHORITY["EPSG","7012"]],AUTHORITY["EPSG","6197"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4197"]],PROJECTION["Transverse_Mercator"],PARAMETER["latitude_of_origin",0],PARAMETER["central_meridian",15],PARAMETER["scale_factor",0.9996],PARAMETER["false_easting",500000],PARAMETER["false_northing",0],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AXIS["Easting",EAST],AXIS["Northing",NORTH],AUTHORITY["EPSG","2312"]]

EPSG:2313 - Kousseri / UTM zone 33N
Proj4:  +proj=utm +zone=33 +ellps=clrk80 +units=m +no_defs 
WKT:  PROJCS["Kousseri / UTM zone 33N",GEOGCS["Kousseri",DATUM["Kousseri",SPHEROID["Clarke 1880 (RGS)",6378249.145,293.465,AUTHORITY["EPSG","7012"]],AUTHORITY["EPSG","6198"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4198"]],PROJECTION["Transverse_Mercator"],PARAMETER["latitude_of_origin",0],PARAMETER["central_meridian",15],PARAMETER["scale_factor",0.9996],PARAMETER["false_easting",500000],PARAMETER["false_northing",0],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AXIS["Easting",EAST],AXIS["Northing",NORTH],AUTHORITY["EPSG","2313"]]

GDAL contains the most complete open source implementation and I'm not aware of any port to Python.

Rasterio does the same kind of thing as GDAL's Python bindings and calls the same C library functions.

>>> from rasterio.crs import CRS
>>> CRS.from_epsg(4326).wkt
'GEOGCS["WGS 84",DATUM["WGS_1984",SPHEROID["WGS 84",6378137,298.257223563,AUTHORITY["EPSG","7030"]],AUTHORITY["EPSG","6326"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4326"]]

Rasterio is not lightweight by any measure.

Check the link below:-

https://github.com/cmollet/sridentify ..............

https://pyproj4.github.io/pyproj/stable/examples.html

>>> from pyproj import CRS
>>> crs = CRS("WGS 84 / UTM Zone 14N")
>>> crs.to_proj4()
<stdin>:1: UserWarning: You will likely lose important projection information when converting to a PROJ string from another format. See: https://proj.org/faq.html#what-is-the-best-format-for-describing-coordinate-reference-systems
'+proj=utm +zone=14 +datum=WGS84 +units=m +no_defs +type=crs'
>>> crs.to_epsg()
32614
>>> print(crs.to_wkt(pretty=True))
PROJCRS["WGS 84 / UTM zone 14N",
    BASEGEOGCRS["WGS 84",
        ENSEMBLE["World Geodetic System 1984 ensemble",
            MEMBER["World Geodetic System 1984 (Transit)"],
            MEMBER["World Geodetic System 1984 (G730)"],
            MEMBER["World Geodetic System 1984 (G873)"],
            MEMBER["World Geodetic System 1984 (G1150)"],
            MEMBER["World Geodetic System 1984 (G1674)"],
            MEMBER["World Geodetic System 1984 (G1762)"],
            ELLIPSOID["WGS 84",6378137,298.257223563,
                LENGTHUNIT["metre",1]],
            ENSEMBLEACCURACY[2.0]],
        PRIMEM["Greenwich",0,
            ANGLEUNIT["degree",0.0174532925199433]],
        ID["EPSG",4326]],
    CONVERSION["UTM zone 14N",
        METHOD["Transverse Mercator",
            ID["EPSG",9807]],
        PARAMETER["Latitude of natural origin",0,
            ANGLEUNIT["degree",0.0174532925199433],
            ID["EPSG",8801]],
        PARAMETER["Longitude of natural origin",-99,
            ANGLEUNIT["degree",0.0174532925199433],
            ID["EPSG",8802]],
        PARAMETER["Scale factor at natural origin",0.9996,
            SCALEUNIT["unity",1],
            ID["EPSG",8805]],
        PARAMETER["False easting",500000,
            LENGTHUNIT["metre",1],
            ID["EPSG",8806]],
        PARAMETER["False northing",0,
            LENGTHUNIT["metre",1],
            ID["EPSG",8807]]],
    CS[Cartesian,2],
        AXIS["(E)",east,
            ORDER[1],
            LENGTHUNIT["metre",1]],
        AXIS["(N)",north,
            ORDER[2],
            LENGTHUNIT["metre",1]],
    USAGE[
        SCOPE["Engineering survey, topographic mapping."],
        AREA["Between 102°W and 96°W, northern hemisphere between equator and 84°N, onshore and offshore. Canada - Manitoba; Nunavut; Saskatchewan. Mexico. United States (USA)."],
        BBOX[0,-102,84,-96]],
    ID["EPSG",32614]]