break exits the loop, not the whole program.
Use exit() or sys.exit() (don't forget to import sys for the second option) to exit the program
Example:
import sys #unnessary if you're using exit() only
colTPNumber = 2
colTDNumber = 3
rows = sheet.iter_rows(min_row=1, max_row=1)
firstRow = next(rows)
for i in firstRow:
if str(i.value) == "TP":
colTPNumber = i.column
elif str(i.value) == "TD":
colTDNumber = i.column
else:
print ("Column name not found")
#break
sys.exit()
#OR
exit()
Some more info:
You can also use quit()
quit() raises the SystemExit exception behind the scenes.
Furthermore, if you print it, it will give a message:
>>> print (quit)
Use quit() or Ctrl-Z plus Return to exit
This functionality was included to help people who do not know Python. After all, one of the most likely things a newbie will try to exit Python is typing in quit.
Nevertheless, quit should not be used in production code. This is because it only works if the site module is loaded. Instead, this function should only be used in the interpreter.
exit() is an alias for quit (or vice-versa). They exist together simply to make Python more user-friendly.
Furthermore, it too gives a message when printed:
>>> print (exit)
Use exit() or Ctrl-Z plus Return to exit
However, like quit, exit is considered bad to use in production code and should be reserved for use in the interpreter. This is because it too relies on the site module.
sys.exit raises the SystemExit exception in the background. This means that it is the same as quit and exit in that respect.
Unlike those two however, sys.exit() is considered good to use in production code. This is because the sys module will always be there.
os._exit exits the program without calling cleanup handlers, flushing stdio buffers, etc. Thus, it is not a standard way to exit and should only be used in special cases. The most common of these is in the child process(es) created by os.fork.
Note that, of the four methods given, only this one is unique in what it does.
Summed up, all four methods exit the program. However, the first two are considered bad to use in production code and the last is a non-standard, dirty way that is only used in special scenarios.
So, if you want to exit a program normally, go with the third method: sys.exit.
Or, even better in my opinion, you can just do directly what sys.exit does behind the scenes and run:
raise SystemExit
This way, you do not need to import sys first.
However, this choice is simply one on style and is purely up to you
Adapted from: https://www.edureka.co/community/16988/python-exit-commands-why-so-many-and-when-should-each-be-used
More info on sys.exit():
sys.exit([arg])
Exit from Python. This is implemented by raising the SystemExit exception, so cleanup actions specified by finally clauses of try statements are honored, and it is possible to intercept the exit attempt at an outer level.
The optional argument arg can be an integer giving the exit status (defaulting to zero), or another type of object. If it is an integer, zero is considered “successful termination” and any nonzero value is considered “abnormal termination” by shells and the like. Most systems require it to be in the range 0–127, and produce undefined results otherwise. Some systems have a convention for assigning specific meanings to specific exit codes, but these are generally underdeveloped; Unix programs generally use 2 for command line syntax errors and 1 for all other kind of errors. If another type of object is passed, None is equivalent to passing zero, and any other object is printed to stderr and results in an exit code of 1. In particular, sys.exit("some error message") is a quick way to exit a program when an error occurs.
Since exit() ultimately “only” raises an exception, it will only exit the process when called from the main thread, and the exception is not intercepted.
Changed in version 3.6: If an error occurs in the cleanup after the Python interpreter has caught SystemExit (such as an error flushing buffered data in the standard streams), the exit status is changed to 120.
From https://docs.python.org/3/library/sys.html
