Create a file named welcome.py$.$ In this file, write a program that takes two command line arguments, which should be the same length. It then reads its input one line at a time, replaces any characters found in the first argument with the corresponding character from the second argument, and prints the result.

For example, to use your program to capitalize its input $($note that user input is mixed with the program's output on the command line$)$:

$[$ee@howtown$]$$ python$3$ welcome.py abcdefghijklmnopqrstuvwxyz ABCDEFGHIJKLMNOPQRSTUVWXYZ and this is the wonder that's keeping the stars apart AND THIS IS THE WONDER THAT'S KEEPING THE STARS APART

Or to censor all lower case vowels:

$[$ee@howtown$]$$ python$3$ welcome.py aeiou $-----$ What I propose, then, is this: that you give Mr$.$ Cummings enough rope. Wh$-$t I pr$-$p$-$s$-,$ th$-$n$,-$s th$-$s: th$-$t y$--$ g$-$v$-$ Mr$.$ C$-$mm$-$ngs $-$n$--$gh r$-$p$-.$ He may hang himself; or he may lasso a unicorn. H$-$ m$-$y h$-$ng h$-$ms$-$lf; $-$r h$-$ m$-$y l$-$ss$---$n$-$c$-$rn$.$

Edge Cases

If your program doesn't get exactly two command line arguments, it should print a usage message and exit immediately:

$[$ee@howtown$]$$ python$3$ welcome.py oops USAGE: welcome.py characters replacements

If your program is given two command line arguments that aren't the same length, it should print an error message and exit immediately:

$[$ee@howtown$]$$ python$3$ welcome.py hi bye ERROR: Arguments must be the same length.

If the same character appears multiple times in the first command line argument, your program should use its last occurrence to determine how to replace it:

$[$ee@howtown$]$$ python$3$ welcome.py aaa xyz with up so floating many bells down with up so flozting mzny bells down

Submission

Test your program manually! When you're confident that it works as intended, upload welcome.py to Gradescope. If you pass all the test cases, you're done. If not, fix the bugs and re$-$upload your file. You can resubmit as many times as you like before the deadline.

Hints

Error messages should be followed by exactly one newline.

There will most likely be newlines in your input. Add the end$=\text{'}\text{'}$ argument to the print$()$ function to keep it from adding more.

If there are no errors, your program should only stop when it reaches the end of its input. On Linux and Mac, use Ctrl$+$D to send an "end of input" signal to your program while testing; on Windows, use Ctrl$+$Z and then Enter.

On Gradescope, you'll only be able to see your program's output; you can't see the input like you can when running locally.

Make sure you only replace each character once. If you're replacing ab with bc$,$ your program should turn cat into cbt; it should not replace the new b with a c and print cct$.$

Your output must match the expected output exactly. Case and spacing matter!