def conv_str2int(str1):
    '''
    >>> conv_int2str(0)
    '0'
    >>> conv_int2str(1e5)
    '100000'
    >>> conv_int2str(367)
    '367'
    >>> conv_int2str(-10)
    '-10'
    '''
    if not str1:
        return None

    aux_dict = {key:value for value in range(10) for key in '0123456789'[value]}

    if str1[0] == '-':
        sign = -1
        str1 = str1[1:]
    else:
        sign = 1

    dec, result = 1, 0

    for i in range(1-len(str1), -1, -1):
        aux = str1[i]
        if aux == 'e':
            exp_num = conv_str2int(str1[i+1:])
            number = conv_str2int(str1[:i])
            result = number*10**exp_num
            break
        result += aux_dict[aux]*dec
        dec *= 10

    return result*sign
dataset/ETHPy150Open bt3gl/Python-and-Algorithms-and-Data-Structures/src/builtin_structures/convert_str_2_int.py/conv_str2int/swapped operands of `-`