python tutorial

Note : if you feel you need to practice the basics of python , please see this

Reading and writing data to files using Python is pretty straightforward. To do this, you must first open files in the appropriate mode. Here’s an example of how to use Python’s “with open(…) as …” pattern to open a text file and read its contents:

with open('data.txt', 'r') as f:
    data = f.read()

open() takes a filename and a mode as its arguments. r opens the file in read only mode. To write data to a file, pass in w as an argument instead:

with open('data.txt', 'w') as f:
    data = 'some data to be written to the file'
    f.write(data)

Note : with is a built-in function that open the file and close it when you are done. So, you don’t need to close your file.

Different Modes to Open a File in Python

Mode	Description
‘r’	Read mode (default)
‘w’	Write mode (truncate file to zero length or create new file)
‘x’	Exclusive creation mode (fail if file already exists)
‘a’	Append mode (write to end of file or create new file)
‘b’	Binary mode (use with ‘r’, ‘w’, or ‘a’ to read or write binary data)
‘t’	Text mode (default; use with ‘r’, ‘w’, or ‘a’ to read or write text data)
‘+’	Open for updating (reading and writing)

writing a dictionary in the file

you need to import json to convert the dict to json format:

import json

details = {'Name': "7amoshka",
		'Age' :20}

with open('convert.txt', 'w') as convert_file:
	convert_file.write(json.dumps(details))

Reading dictionary from the file

import json

with open('dictionary.txt') as f:
	data = f.read()
	
# reconstructing the data as a dictionary
js = json.loads(data)
print(js)

writing a list in the file

names = ['Jessa', 'Eric', 'Bob']

with open(r'E:/demos/files_demos/account/sales.txt', 'w') as fp:
    for item in names:
        # write each item on a new line
        fp.write("%s\n" % item)

Reading a the data as a list