def commander(crew):
    """
    Actions to perform with each '1' obtained in the roll.
    It must ask if you want to change any crew member or re-roll
    available crew.
    It will need to validate all user input.
    It needs the crew array and returns it modified

    Parameters
    ----------
    crew : array
        Result of the dice roll.

    Returns
    -------
    crew : array
        Dice roll result modified by commander.

    """

    print('Commander available:')
    # The key pressed by the user is stored in 'c'.
    c = 'x'
    oldcrew = ''
    # Prompt until a valid value is obtained
    while c.lower() != 'c' and c.lower() != 'r':
        c = input("Do you want to change any members of your crew (c) \n \
        or re-roll de dice (r)? c/r\n")
    if c.lower() == 'c':
        # At this point 'c' is used to validate that the number is on the
        # 'crew' (an unavailable crew member cannot be changed)
        c = 'n'
        while c == 'n':
            # 'cont' stores the position in the array in which
            # the indicated value is located
            cont = 0
            oldcrew = int(input("Number of the crew member to be replaced:"))
            # If a 6 (scanner) has been indicated, it moves on to the next
            # iteration without doing anything else (continues requesting
            # a crew member until a valid value is received)
            if oldcrew == 6:
                continue
            for i in crew:
                if i == oldcrew:
                    # If the entered value is available, the new value is
                    # requested, making sure that a value between 2 and 5
                    # was indicated.
                    newcrew = 1
                    while newcrew < 2 or newcrew > 5:
                        newcrew = int(
                            input("Value of the new crew member (2-5)"))
                    crew[cont] = newcrew
                    # 'c' is updated to stop prompting.
                    c = ''
                    break
                cont += 1
    elif c.lower() == 'r':
        ncrew = []
        cont = 0
        while cont < len(crew):
            if crew[cont] == 1 or crew[cont] == 6:
                ncrew.append(crew[cont])
            else:
                ncrew.append(randint(1, 6))
            cont += 1
        # Crew update
        crew = ncrew
    if c == 'c':
        print(f'Successfully changed {oldcrew} to {newcrew}')
    print(f"Nueva tripulación: {crew}")
    pretty_shown_crew(crew)
    return crew