Working with Files and Paths in Python

Importing Required Modules

Python provides the os module to work with file system paths. To use its path-related functions, import os.path:

import os.path
print(dir(os.path))

Some useful functions from os.path:

• exists(path): Checks if a given path exists.
• abspath(path): Returns the absolute path of a given file or directory.
• basename(path): Returns the base name of the given file or directory.
• isdir(path): Checks if the given path is a directory.
• isfile(path): Checks if the given path is a file.
• islink(path): Checks if the given path is a symbolic link.
• realpath(path): Returns the canonical path of the specified filename.

Checking If a Path Exists and Its Type

The following code checks whether a given path exists and determines if it is a file or directory:

import os 
path = "F:\\b45\\book1.xlsx"
if os.path.exists(path):
  if os.path.isdir(path):
    print("It is a directory")
  elif os.path.isfile(path):
    print("It is a file")
  elif os.path.islink(path):
    print("It is a link")
else:
  print("Path does not exist")

Checking another path:

path1 = "f:\\dir1"
if os.path.exists(path1):
  print("It is a directory")
else:
  print("Path does not exist")

Working with file paths:

path = "file.txt"
if os.path.exists(path):
  print(os.path.abspath(path))
  print(os.path.realpath(path))
  print(os.path.basename(path))

Checking Path Existence and Counting Files in a Directory

import os

def check(path):
    if os.path.exists(path):
        if os.path.isdir(path):
            dir_list = os.listdir(path)
            return len(dir_list)
        if os.path.isfile(path):
            return os.path.basename(path)

dirp = "F:\\People\\durgareddy\\dir1"

Listing Python Files in a Directory

for root, dirs, files in os.walk("d:/ee"):
  for file in files:
    if file.endswith(".py"):
      print("Python file:", file)

File Handling in Python

To handle files in Python, we can:

• Open and close files
• Read, write, and append data

File Access Modes

• Read: 'r'
• Write: 'w'
• Append: 'a'

Opening a File

filename = "file.txt"
file = open(filename, "r") 
filecontent = file.read()
print(filecontent)
print(type(filecontent))
print(filecontent.count("error"))

This script reads the content of file.txt, prints its content, data type, and counts occurrences of the word "error" in the file.