log - Providing easy logging to your project

Purpose:

This is a small class module designed as a central log file creator.

The calling program is responsible for passing the proper arguments to create the log file header. For example:

(printheader=True, headertext='some,header,text,here')

It is suggested to initialise the Log class at program startup, with the printheader parameter set to True. This is safe because if the log file already exists, the header will not be re-created. However, if the log file does not exist, it will be created with a header, using the value of the headertext parameter.

Platform:

Linux/Windows | Python 3.7+

Developer:

J Berendt

Email:

support@s3dev.uk

Comments:

n/a

Example:

To use the Log class in your project:

>>> from utils4.log import Log

>> header = 'COMMENT,TYPE,VAL,UNIT'
>> logger = Log(filepath='/tmp/testlog.log',
                printheader=True,
                headertext=header)
>> logger.write(text='Most cows can jump over the moon,Fact,94.2,pct')

class log.Log(filepath, *, autofill=True, printheader=False, headertext='', sep=',')

This is a small and simple log file creator/writer class.

The calling program is responsible for passing the proper arguments to create the log file header. For example:

(printheader=True, headertext='some,header,text,here')

On class instantiation, validation is performed to determine if the log file exists. If the log file does not exist, a header is required before writing to the log file. These parameters can be passed to the class on instantiation, and will be ignored if the log file already exists.

Parameters:

• filepath (str) – Full path to the log file.

• autofill (bool, optional) – Automatically populate datetime.now(), host and username values, to each log entry. Defaults to True.

• printheader (bool, optional) –

  Print a log file header using the text passed into the headertext parameter. Defaults to False.

  Note

  The header will only be written if the log file does not exist.

• headertext (str, optional) – String of delimited column labels to be written as the header. Defaults to ‘’.

• sep (str, optional) – Separator to be used in the log file. This separator is used when writing the autofill values. Defaults to ‘,’.

File Validation:

On class instantiation, tests are performed to ensure the log file is being populated in a logical way.

• If printheader is False, and the log file does not exist, the user is notified.

• If printheader is True, yet headertext is blank, the user is instructed to pass header text.

• If printheader is True, yet the log file already exists, the header will not be written.

Example:

To use the Log class in your project:

>>> from utils4.log import Log

>>> header = 'COMMENT,TYPE,VAL,UNIT'
>>> logger = Log(filepath='/tmp/testlog.log',
                 printheader=True,
                 headertext=header)

>>> logger.write(text='Most cows can jump over the moon,Fact,94.2,pct')

__init__(filepath, *, autofill=True, printheader=False, headertext='', sep=',')

Log class initialiser.

write(text: str)

Write text to the log file defined at instantiation.

Parameters:

text (str) – Delimited text string to be written to the log.

Note

If autofill is True, the datetime, host and username values will be populated automatically; these do not need to be passed into the text argument.

Design:

If the autofill argument is True, the current datetime, host and username values are written (in that order), ahead of the text string provided to the text argument. The sep parameter (defined at instantiation), is used to separate these auto-populated fields.

Example:

To write to the log file:

>>> from utils4.log import Log

>>> logger = Log(filepath='/tmp/testlog.log, autofill=True)
>>> logger.write(text='Just adding some random text to my log')

write_blank_line()

Write a blank line to the log file.

Note

The autofill information is not written. This is a true blank line, created by writing the system’s native line separator character(s)to the log.

Example:

To write a blank line to the log file:

>>> from utils4.log import Log

>>> logger = Log(filepath='/tmp/testlog.log', autofill=True)
>>> logger.write_blank_line()