How do I select shapefiles to be converted to GeoJSON in folder with multiple shapefiles?

Question

How do I only select .shp's to read and then convert to .geojson. The homefolder has 3 different shapefiles and this code currently converts every single file in the folder to a .json. Just trying to speed up the running process. I have some other issues too with naming conventions that I will deal with next. Among other things, this is a work in progress.

homefolder = "D:/UW/Winter_2016/501/pythonProject/publicLandsData/newShapefiles/"

# read the shapefiles
filenames = os.listdir(homefolder)

for filename in filenames:
  reader = shapefile.Reader(homefolder + os.path.splitext(os.path.basename(filename))[0])
  print filename 
  fields = reader.fields[1:]
  field_names = [field[0] for field in fields]
  buffer = []
  print filename + "buffer dictionary done"
  for sr in reader.shapeRecords():
      atr = dict(zip(field_names, sr.record))
      geom = sr.shape.__geo_interface__
      buffer.append(dict(type="Feature", \
      geometry=geom, properties=atr)) 

# write the GeoJSON file
#currently it saves into the wrong directory..and all one shapefile, might be nice to be in multiple geojson's 
#list directory "homefolder" in variable filenames
  filenames = os.listdir(homefolder)

  for filename in filenames:
#for loop to rename local government to loca
    geojson = open(((os.path.splitext(os.path.basename(filename))[0]) + ".json"), "w")
    #os.rename(os.path.join(homefolder, filename), os.path.join(homefolder, (filename.replace('.shp', 'shp'))))
    geojson.write(dumps({"type": "FeatureCollection",\
      " features": buffer}, indent=2) + "\n")
    geojson.close()

I have tried using basename, selecting only ".shp" files with .endwith() etc to no avail. Suggestions?

I found this shp to geojson conversion code at the link below: https://gist.github.com/frankrowe/6071443

Answer 1

Try replacing line 4 with this:

filenames = [ f for f in os.listdir(homefolder) if os.path.isfile(os.path.join(homefolder,f)) and f.endswith(".shp")]

This will create a list containing only files with the extension ".shp"

Expanded for clarity:

# create empty list
filenames = []
# begin iterating over files in homefolder directory
for f in os.listdir(homefolder):
    # if the file is indeed a file and it ends with .shp append the name to the list
    if os.path.isfile(os.path.join(homefolder,f)) and f.endswith(".shp"):
        filenames.append(f)

Answer 2

Look at PyShp_geointerface.py with a generator

import shapefile
def records(filename):
   # generator
   reader = shapefile.Reader(filename)
   fields = reader.fields[1:]
   field_names = [field[0] for field in fields]
   for sr in reader.shapeRecords():
      geom = sr.shape.__geo_interface__
      atr = dict(zip(field_names, sr.record))
      yield dict(geometry=geom,properties=atr)
 # for one file
  buffer = [rec for rec in records('shapefile.shp')]
  result = {"type": "FeatureCollection"," features": buffer}

For many files, simply loop through the files

for dir, subdir, files in os.walk(a_folder):
    for fname in files:
        if fname.endswith(".shp"):
           buffer = [rec for rec in records(os.path.join(dir, fname))]
           result = {"type": "FeatureCollection"," features": buffer}
           # write the resulting GeoJSON file
           name = os.path.splitext(fname[0]+'.geojson')
           with open(name, "w") as outfile:
               json.dump(result,outfile)