Open a File on the Server
Assume we have the following file, located in the same folder as Python:
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")
print(f.read())
If the file is located in a different location, you will have to specify the file path, like this:
Example
f = open("D:\\myfiles\welcome.txt")
print(f.read())
Using the with statement
You can also use the with statement when opening a file:
Example
with open("demofile.txt") as f:
print(f.read())
Then you do not have to worry about closing your files, the with statement takes care of that.
Close Files
It is a good practice to always close the file when you are done with it.
If you are not using the with statement, you must write a close statement in order to close the file:
Example
f = open("demofile.txt")
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.
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
with open("demofile.txt") as f:
print(f.read(5))
Read Lines
You can return one line by using the readline() method:
Example
with open("demofile.txt") as f:
print(f.readline())
By calling readline() two times, you can read the two first lines:
Example
with open("demofile.txt") as f:
print(f.readline())
print(f.readline())
By looping through the lines of the file, you can read the whole file, line by line:
Example
with open("demofile.txt") as f:
for x in f:
print(x)
