Archive
Archive for June, 2016
for / else and try / except / else
June 17, 2016
1 comment
Problem
What is that “else” in a for loop? And that “else” in an exception handler?
Solution
They can be confusing but in this thread I found a perfect way to remember what they mean. Asdayasman suggests that we should always annotate these “else” branches:
for _ in []:
...
else: # nobreak
...
try:
...
except:
...
else: # noexcept
...
To be honest, IMO it is best to avoid for / else completely.
email notification from a script
June 15, 2016
1 comment
Problem
You want to send an email to yourself from a script.
Solution
You can find here how to do it from a Bash script. That solution uses the mailx command.
Here is a simple Python wrapper for the mailx command:
#!/usr/bin/env python3
# coding: utf8
import os
DEBUG = True
# DEBUG = False
class NoSubjectError(Exception):
pass
class NoRecipientError(Exception):
pass
def send_email(to='', subject='', body=''):
if not subject:
raise NoSubjectError
if not to:
raise NoRecipientError
#
if not body:
cmd = """mailx -s "{s}" < /dev/null "{to}" 2>/dev/null""".format(
s=subject, to=to
)
else:
cmd = """echo "{b}" | mailx -s "{s}" "{to}" 2>/dev/null""".format(
b=body, s=subject, to=to
)
if DEBUG:
print("#", cmd)
#
os.system(cmd)
def main():
send_email(to="[email protected]",
subject="subject")
#
send_email(to="[email protected]",
subject="subject",
body='this is the body of the email')
#############################################################################
if __name__ == "__main__":
main()
You can also find this code as a gist.
Python Adventures 