File_open.py

# Python File Open
# Open a File on the Server
# Assume we have the following file, located in the same folder as Python:

# demofile.txt

# Hello! Welcome to demofile.txt
# This file is for testing purposes.
# Good Luck!
# To open the file, use the built-in open() function.

# The open() function returns a file object, which has a read() method for reading the content of the file:

# Example
f = open("demofile.txt", "r")
print(f.read())

# If the file is located in a different location, you will have to specify the file path, like this:

# Example
# Open a file on a different location:

f = open("D:\\myfiles\welcome.txt", "r")
print(f.read())

# Read Only Parts of the File
# By default the read() method returns the whole text, but you can also specify how many characters you want to return:

# Example
# Return the 5 first characters of the file:

f = open("demofile.txt", "r")
print(f.read(5))

# Read Lines
# You can return one line by using the readline() method:

# Example
# Read one line of the file:

f = open("demofile.txt", "r")
print(f.readline())

# By calling readline() two times, you can read the two first lines:

# Example
# Read two lines of the file:

f = open("demofile.txt", "r")
print(f.readline())
print(f.readline())

# By looping through the lines of the file, you can read the whole file, line by line:

# Example
# Loop through the file line by line:

f = open("demofile.txt", "r")
for x in f:
  print(x)

# Close Files
# It is a good practice to always close the file when you are done with it.

# Example
# Close the file when you are finish with it:

f = open("demofile.txt", "r")
print(f.readline())
f.close()

# *Note: You should always close your files, in some cases, due to buffering, changes made to a file may not show until you close the file.