Is your feature request related to a problem? Please describe.

Consider can.logger being used on an embedded Linux system. A python can.logger ... process is started as a daemon (/etc/init.d/) in boot and killed in shutdown. When the system is restarted, the existing log file on the device and its contents is currently overwritten. This results in a loss of data.

Describe the solution you'd like

Upon executing python can.logger ... the program should check to see if the specified log file exists. If it does exist, then the file should be appended to.

Describe alternatives you've considered

An optional argument could be added (perhaps -a or -w) to give the user the option as to whether an existing file, if found, should be overwritten or appended to.

Additional context

P.S. Feel free to assign this issue to me. I should be around to it by Sunday or Monday.