Reverse Word Order

Lesson: Reverse Words

Create a function that

  • takes a single string argument and
  • returns a string with the words of the original argument in reversed order

E.g. when given "Mary says hi" the function returns "hi says Mary".

Optionally: Create a Python script reverse_words.py that takes a string command line argument and prints the words of this argument in reversed order. E.g. when executed as

python3 reverse_words.py "Mary says hi" the program prints "hi says Mary".

Optionally: Add options to the function and the script that allow for returning/printing the result string

  1. You can access the command line arguments through sys.argv.

  2. Python features an extensive command line parsing library in the stlib: argparse.

    • reversed or unreversed and that in
    • all-uppercase, all-lowercase, titlecase or capitalized.

  3. Use help("") or help(str) to learn useful string methods.

Example reverse_order-function 
>>> def reverse_order(words):
...     list_of_words= words.split(' ')
...     list_of_words.reverse() # NOTE: reverse is inplace
...     return ' '.join(list_of_words)
... 
>>> reverse_order("Mary says hi")
'hi says Mary'
>>>
Example reverse_words.py Script
reverse_words.py


python3.8 reverse_words.py --help

python3.8 reverse_words.py --word "Hi says Mary" --format_style capitalize --reverse