Creating a temporary file without tempfile module
The task of a temporary file can be done without using tempfile module by creating a simple file. For this, you have to create a normal file, do the temporary tasks and remove the file after completing the tasks. In this example, a temporary file named temp.txt is opened with write mode and a text is written in the temporary file. ‘os’ module is used here to read the content of the temp.txt file and remove the file after completing the task.
import os
# Define the name of the temporary file
filename = 'temp.txt'
# Open the file in reading mode
fh = open(filename, 'w')
try:
# Print a message before writing
print("Writing to the file>>>\n")
# Write a string to the file
fh.write("Testing temp file")
# Close the file after writing
fh.close()
finally:
# Print a message before reading
print("<<<Reading from the file")
# Run bash command to read the file
os.system("cat temp.txt")
# Print newline
print("\n")
# Remove the temporary file
os.remove(filename)
Output:
Run the script. The following output will appear after running the script.
Creating temporary file using TemporaryFile() method
tempfile module is used in this example to create a temporary file. This module has many methods to work with the temporary file. TemporaryFile() method is used here to create a temporary file. The temporary file is opened in the script as a text file in write mode. The temporary file will be created in the current location by default. Two lines of text is written in the temporary file by using write() method. Next, seek() method is called to set the file pointer at the starting of the file. The content of the file is printed in the terminal by using read() method. close() method of the module is used to close the file and remove the file automatically.
import tempfile
# Declare object to open temporary file for writing
tmp = tempfile.TemporaryFile('w+t')
try:
# Print message before writing
print('Writing to the temporary file...')
# Write data to temporary file
tmp.write('Linux Hint\n')
tmp.write('The content of temporary file')
# Move to the starting of the file
tmp.seek(0)
# Read content of the temporary file
print('Reading temporary file: \n{0}'.format(tmp.read()))
finally:
# Remove the temporary file automatically
tmp.close()
Output:
Run the script. The following output will appear after running the script.
Creating temporary file using NamedTemporaryFile() method
In the previous example, the name of the temporary file creates randomly. But if you want to set any custom name for the temporary file then you have to use NamedTemporaryFile() method for creating a temporary file. In this example, a temporary file is opened in write mode using NamedTemporaryFile() method. Next, the file name is set to temp.txt. One line of text is written to the file and read from the file like the previous example. It is mentioned before that the temporary file deletes automatically when close() method is called. After delete, ‘os’ module is used here to check the temporary file exists or not.
import tempfile
# Import os module
import os
# Declare object to open temporary file for writing
tmp = tempfile.NamedTemporaryFile('w+t')
# Declare the name of the temporary file
tmp.name="temp.txt"
try:
# Print message before writing
print('Write data to temporary file...')
# Write data to the temporary file
tmp.write('This is a temporary content.')
# Move to the starting of the file
tmp.seek(0)
# Read content of the temporary file
print('Read the content of temporary file: \n{0}'.format(tmp.read()))
finally:
# Remove the file automatically
tmp.close()
# Check the file exist or not
if(os.path.exists(tmp.name)):
print('The file exist')
else:
print('The file does not exist')
Output:
Run the script. The following output will appear after running the script.
Creating a temporary file with prefix and suffix
All temporary files are created in the current location for the previous examples. The location of the temporary file and, the prefix and suffix for the temporary filename can be mentioned at the time of file creation using NamedTemporaryFile() method. According to the following script, The temporary filename will start with ‘tm_’ and end with ‘_fl’. The file will store in the ‘/tmp’ folder. After creating the file, the temporary filename is printed by using ‘name’ property. Next, ‘os’ module is used to check the file is removed or not.
import tempfile
# Import os module
import os
# Declare object to create a temporary file with suffix and prefix
tmp = tempfile.NamedTemporaryFile(mode='w+t', prefix='tm_',
suffix='_fl',
dir='/tmp')
# Print the temporary filename
print(tmp.name)
try:
# Print message before writing
print('Write data to temporary file...')
# Write data to a temporary file
tmp.write('This is a temporary content.')
finally:
# Remove the file automatically
tmp.close()
if(os.path.exists(tmp.name) == False):
print('File is removed')
Output:
Run the script. The following output will appear after running the script.
Conclusion:
It is a common requirement for any programming language to create a temporary file to do many tasks on demand and work with those data that is not required to store permanently. Some necessary methods of tempfile module are explained in this article to show the ways to use the temporary file. I, hope, the reader will be able to create and use temporary files easily after reading this article.
