Ascend, Descend, Repeat?

DESCRIPTION:

You are given three integer inputs: length, minimum, and maximum.

Return a string that:

1. Starts at minimum
2. Ascends one at a time until reaching the maximum, then
3. Decends one at a time until reaching the minimum
4. repeat until the string is the appropriate length

Examples:

 length: 5, minimum: 1, maximum: 3   ==>  "12321"
 length: 14, minimum: 0, maximum: 2  ==>  "01210121012101"
 length: 11, minimum: 5, maximum: 9  ==>  "56789876567"

Notes:

• length will always be non-negative
• negative numbers can appear for minimum and maximum values
• hyphens/dashes ("-") for negative numbers do count towards the length
• the resulting string must be truncated to the exact length provided
• return an empty string if maximum < minimum or length == 0
• minimum and maximum can equal one another and result in a single number repeated for the length of the string

def ascend_descend(length, minimum, maximum):
    tempStr=""
    if minimum==maximum:
        tempStr+=str(minimum)*length
    if length==0:
        return ''
    if maximum<minimum:
        return ''
    while len(tempStr)<length:
        for i in range(minimum,maximum):
            if len(tempStr)>length:
                break
            else:
                tempStr+=str(i)
        for i in range(maximum,minimum,-1):
            if len(tempStr)>length:
                break
            else: 
                tempStr+=str(i)
    return (tempStr[:length])