open file with python code example

Example 1: python write to file

file = open(“testfile.txt”,”w”) 
 
file.write(“Hello World”) 
file.write(“This is our new text file”) 
file.write(“and this is another line.”) 
file.write(“Why? Because we can.”) 
 
file.close()

Example 2: python read file

with open("file.txt", "r") as txt_file:
  return txt_file.readlines()

Example 3: read file python

document = 'document.txt'
file = open(document, 'r')
# 'r' can be replaced with:
# 'w' to write
# 'a' to append (add to the end)
# 'w+' makes a new file if one does not already exist of that name
# 'a+' is the same as 'w+' but it appends if the file does exist

##go to beginning of document
file.seek(0)

##print all lines in document, except empty lines:
for i in file:
    k = i.strip() 
    print k

##close the file after you are done
file.close()


##this can temporarily open a file:
with open(document) as ur:
    for i in ur:
        k = i.strip() 
        print k

Example 4: python open file

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 5: python with file.open

# Reference https://docs.python.org/3/library/functions.html#open

# Method 1
file = open("welcome.txt", "r") # mode can be r(read) w(write) and others 
data = file.read()
file.close()

# Method 2 - automatic close
with open("welcome.txt") as infile:
  data = file.read()

Example 6: python file reading

fin = open("NAME.txt", 'r')
body = fin.read().split("\n")
line = fin.readline().strip()