Incorrect size of file in Python

You didn't close your file before trying to get its size, as you do it inside the with block. Take it outside:

import os

def create_python_script(filename):
    comments = "# Start of a new Python Program"
    #filesize = 0
    with open(filename, 'w') as new_file:
        new_file.write(comments)
        cwd=os.getcwd()
        fpath = os.path.abspath(filename)
        print(fpath)

    filesize=os.path.getsize(fpath)
    return(filesize)

print(create_python_script('newprogram.py'))
# 31

First opening the file with write permissions to add the text in the file. Then opening the file with read permissions to get the size of the file.

import os

def create_python_script(filename):
    comments = "# Start of a new Python program"
    with open(filename, 'w') as pd:
        pd.write(comments)

    with  open(filename, "r"):
        filesize = os.path.getsize(filename)
        print(filesize)
    return filesize

print(create_python_script("program.py"))

import os

def create_python_script(filename):
  comments = "# Start of a new Python program"
  with open(filename, 'w') as file:
    file.write(comments)
    file.close()
    filepath = os.path.abspath(filename)
    filesize = os.path.getsize(filepath)
  return(filesize)

print(create_python_script("program.py"))

#this will give you correct result

This one is working perfectly too!

    def create_python_script(filename):
      import os
      comments = "# Start of a new Python program"
      with open(filename,'w')as file:
         file.write(comments)
      filesize = os.path.getsize(filename)
      return(filesize)
    print(create_python_script("program.py"))