filesplitter.py

#! /usr/bin/env python3
###
#  filesplitter.py
#syntax is:
#   ./filesplitter.py filename linesPerFile
###

import sys,os

class myfile(object):

    def __init__(self):
        self.data = ''
        self.fname = ''
                    
    def readFile(self, fname, commenter=None):
        #tries to read actual file into list split by \n
        self.inFile = fname
        sfile = ''

        #check if file exists
        if os.path.isfile(str(fname)):
            #get absolute path:
            fname = os.path.abspath(fname)
            print('trying to read file: ' + fname)
            with open(fname, 'r') as f:
                print("file is opened")
                sfile = f.readlines() #read the lines into a list
                
                f.close()
                
            #assign to class var:
            self.fname = fname
        else:
            #attempt to use the fname var like an io object
            try:
                sfile = fname.readlines()
                fname.close()
                self.fname = fname.name
                self.isFile = True
            except AttributeError:
                print('file does not exist: ' + str(fname))
                return False
                
        if sfile:        
            print("file was read")
            if commenter:
                #trim comments and remove blank lines:
                sfile = [line[:line.find(commenter)] for line in sfile if line[:line.find(commenter)]]
            if sfile[0] == '\ufeff':
                #strip unicode BOM
                sfile = sfile[1:]
                
            self.data = sfile
            return True
        else:
            print('file could not be read')
            return False
            
        return True

    def returnData(self):
        return self.data

    def getColumnNames(self):
        cols = [col for col in self.data[0]]
        return cols
        
    def split(self, linesPerFile):
        hdr = self.data[0] # repeats per file
        if linesPerFile <= 0:
            linesPerFile = 50 #reasonable default
            
        nFile = 0
        nLine = 0
        of = 0
        for row in self.data[1:]:
            if nLine == 0:       
                if of:
                    of.close()                    
                #create new file and print header
                oFileName = self.inFile + str(nFile)
                print("writing output to file: " + oFileName)
                of = open(oFileName, 'w')
                of.write(hdr + '\n')
                nFile += 1
                
            of.write(row + '\n')
            nLine += 1
            if nLine > linesPerFile:
                nLine = 0

        if of:
            of.close()
        print("done writing file")


if __name__ == '__main__':
    
    mydata = myfile()   

    if len(sys.argv) > 1:
        fname = sys.argv[1]
        linesPerFile = sys.argv[2]
    else:
        print("no args, assigning test case:")
        fname = 'fakedata.csv'
        print(fname)

    if mydata.readFile(fname, '!'):
        mydata.split(linesPerFile)