Retrieving size of shapefile in ArcPy?

Iterate through all files in the shapefile directory with a valid shapefile extension and add their sizes together. The os module is helpful for this task. Here's a function that returns the size of all shapefile files associated with an input shapefile in bytes. Use the full path of the shapefile as your input.

import os

def ShpSize (inShp):
    #standardize lowercase
    inShp = inShp.lower ()
    #shapefile extensions
    extensions = [".shp",
                  ".shx",
                  ".dbf",
                  ".sbn",
                  ".sbx",
                  ".fbn",
                  ".fbx",
                  ".ain",
                  ".aih",
                  ".atx",
                  ".ixs",
                  ".mxs",
                  ".prj",
                  ".xml",
                  ".cpg"]

    #shape file name without directory
    shpName = os.path.basename (inShp)
    #shape file name without .shp extension
    shpFlName = os.path.splitext(shpName)[0]

    #size set to zero
    size = 0
    #directory of shapefile
    shpDir = os.path.dirname (inShp)
    #iterate directory files
    for fl in os.listdir (shpDir):
        #standardize lowercase
        fl = fl.lower ()
        #skip file names that don't match shapefile
        flName = os.path.splitext(fl)[0]
        if not flName == shpFlName:
            #special case: .shp.xml file
            if not fl == shpFlName + ".shp.xml":
                continue
        #skip file names without proper extension
        ext = os.path.splitext(fl)[1]
        if not ext in extensions:
            continue
        #get size
        flFullPath = os.path.join (shpDir, fl)
        size += os.path.getsize (flFullPath)

    return size

You can use a generator expression to efficiently find the shapefile size (i.e. including all associated files). The following method uses built-in Python 2.7 functionality.

import os, glob

ws = r'C:\path\to\your\shapefiles'  # input workspace

shapefiles = glob.glob(os.path.join(ws, "*.shp")) # List all .shp files

for shapefile in shapefiles:
    s = sum([os.stat(x).st_size for x in glob.glob(shapefile.split(".")[0] + "*")])
    print "The file size for %s is %s bytes or %s kb" % (shapefile, s, (float(s)/1000))

The generator expression does the following:

1. List all of the associated files of a shapefile. In this case, strip off the ".shp" extension from the path and use glob with the path and wildcard * to list all of the associated files
2. Get the file sizes in bytes using os.stat
3. Sum them using the generator sum([...]).