Convert an integer into standard form-CodePudding

I am trying to create a function to convert an integer into standard form (a * 10 ** n, where 1 ≤ a < 10). I have the following code, which raises countless errors and most likely does not work, but you can see my approach:

# The power of ten is always the amount of digits minus one
    power = len(str(num)[:-2]) - 1

    # Count trailing zeroes (until a number not zero)
    zero_count = 0

    for digit in reversed(str(num)[-2]):
        print(digit)
        if digit == "0":
            zero_count  = 1
        else:
            break
    
    # Chop the trailing zeroes off the end
    add = str(num)[:-zero_count]
    
    # Divide the add until it is less than ten
    while add > 10:
        add = add / 10
    
    # Formatting
    standard_form = f"{add} * 10 ** {power}"

However, nothing I have done to debug it has worked. How can I convert number N into standard form?

CodePudding user response：

I would use a recursive function:

def sform(add, power=0):
    if 1 <= abs(add) < 10:
        return add, power
    elif 0 < abs(add) < 1:
        return sform(add*10, power-1)
    elif add == 0:
        return (0, 0)
    return sform(add/10, power 1)

def test_sform(num):
    add, power = sform(num)
    print(f"{add} * 10 ** {power}")

Tests:

>>> test_sform(234864897363)
2.34864897363 * 10 ** 11
>>> test_sform(-1234)
-1.234 * 10 ** 3
>>> test_sform(0.5)
5.0 * 10 ** -1
>>> test_sform(1.375e-06)
1.3749999999999998 * 10 ** -6
>>> test_sform(-0.75)
-7.5 * 10 ** -1
>>> test_sform(10)
1.0 * 10 ** 1
>>> test_sform(1)
1 * 10 ** 0
>>> test_sform(0)
0 * 10 ** 0