files with python code example

Example 1: open file python

with open('filename', 'a') as f: # able to append data to file
	f.write(var1) # Were var1 is some variable you have set previously
	f.write('data') 
	f.close() # You can add this but it is not mandatory 

with open('filename', 'r') as f: # able to read data from file ( also is the default mode when opening a file in python)

with open('filename', 'x') as f: # Creates new file, if it already exists it will cause it to fail

with open('filename', 't') as f: # opens the file in text mode (also is defualt)

with open('filename', 'b') as f: # Use if your file will contain binary data
  
with open('filename', 'w') as f: # Open file with ability to write, will also create the file if it does not exist (if it exists will cause it to fail)
  
with open('filename', '+') as f: # Opens file with reading and writing

# You can combine these as you like with the + for reading and writing

Example 2: read files and write into another files python

import sys
import glob
import os.path

list_of_files = glob.glob('/Users/Emily/Topics/*.txt') #500 files

for file_name in list_of_files:
    print(file_name)

    # This needs to be done *inside the loop*
    f= open(file_name, 'r')
    lst = []
    for line in f:
       line.strip()
       line = line.replace("\n" ,'')
       line = line.replace("//" , '')
       lst.append(line)
    f.close()

    f=open(os.path.join('/Users/Emily/UpdatedTopics',
    os.path.basename(file_name)) , 'w')

    for line in lst:
       f.write(line)
    f.close()

Example 3: how to open a text file in python

f = open("demofile2.txt", "a")
f.write("Now the file has more content!")
f.close()