Question & Answer: Define and test a function myRange. This function should behave like Python’s standard range fun…..

Explanation::

• Code for myRange() is provided below. Code runs without any error.
• Code is developed in pyCharm software.
• Every detail is provided in code itself.
• All important syntax and variable are explained well in comments format.
• myRange() has *args as parameter like this -> def myRange(*args) in its definition.
• *args is used when there are variable number of parameters depending on the calls. Any number of parameters can be passed.
• But for myRange() at maximum we have used three parameters.
• Read comments for better understanding of the code.
• If you get identation issues after copying the code, then I have provided screenshots of the code too. So refer them if any error occurs.

Code in python::

"""
   In function named myRange(*args), I have created a list called myList
   which is returned at the end of the function.
   There are three condtitions of if/elif/else for 1,2 and 3 number of arguments respectively.
   Every code below is explained well in comments format.
"""
def myRange(*args):
    myList=[]
    if len(args) is 1:
        """
         This condtition is true when there is only one parameter passed into function.
          Variable k is created and it is initialized to 0.
          Now passed value can be either positive(>0) or negative(<0) or 0 itself(empty list returned).
        """
        k=0
        if args[0] > 0:
            """
            If parameter is positive, a while loop is run starting from k=0 to args[0]
            args[0] itself is not added in the list. For eg if args[0]=5 then myList=[0,1,2,3,4] is returned.
            In every iteration of loop, variable k is added into the list and incremented by 1 i.e k=k+1.
            """
            while k < args[0]:
                myList.append(k)
                k=k+1
        else:
            """
            If parameter is negative, a while loop is run starting from k=0 to args[0]
            args[0] itself is not added in the list. For eg if args[0]= -5 then myList=[0,-1,-2,-3,-4] is returned.
            In every iteration of loop, variable k is added into the list and decremented by 1 i.e k=k-1.
            """
            while k > args[0]:
                myList.append(k)
                k=k-1


    elif len(args) is 2:
        """
        This condition is true when there are two parameters passed into the function.
        First parameter i.e args[0] is starting value of range.
        Second parameter i.e args[1] is ending value of range.
        Variable k is declared and initialized to args[0](Starting value of range)
        If both parametere are same i.e args[0]==args[1] then an empty list is returned.
        """
        k = args[0]
        if args[0] < args[1]:
            """
            If args[0] < args[1], here while loop run from k=args[0] upto args[1].
            For eg args[0]=4 and args[1]=10, then myList=[4,5,6,7,8,9] is returned.
            In every iteration of while loop value k is appended into the list and
            k is incremented by 1 i.e k=k+1.
            Here args[1] itself is not added.
            """
            while k < args[1]:
                myList.append(k)
                k=k+1
        else:
            """
              If args[0] > args[1], here while loop run from k=args[0] upto args[1].
              For eg args[0]=10 and args[1]=4, then myList=[10,9,8,7,6,5] is returned.
              In every iteration of while loop value k is appended into the list and
              k is incremented by 1 i.e k=k+1.
              Here args[1] itself is not added.
            """
            while k > args[1]:
                myList.append(k)
                k=k-1
    else:
        """
        This condition is for three parameters passed into function.
         It is similar to 2 parameter functioning, here instead of increasing value k by 1, 
         it is incremented by third parameter i.e args[2].
        """
        k=args[0]
        if args[0] < args[1]:
            while k < args[1]:
                myList.append(k)
                k=k+args[2]
        else:
            while k > args[1]:
                myList.append(k)
                k=k+args[2]

    """
      Finally at the end myList is returned 
    """
    return myList



"""
Calling myRange() function with different parameters as follows.
"""
print("=================One parameter function call===================")
print(myRange(10))
print(myRange(-10))

print("=================Two parameter function call===================")
print(myRange(10,20))
print(myRange(10,-10))
print(myRange(10,10)) #same parameters

print("=================Three parameter function call===================")
print(myRange(2,25,3))
print(myRange(25,2,-3))

Output::

Screenshots of the code for identation….refer line number of the code on every pictures.

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