If the # sign is found in the format string, this selects the alternate form of the given format. Not all formats have an alternate form; the alternate form is different depending on the format. Refer to the format descriptions below for details on the alternate format.
When printing signed values, always display the sign (prefix with either '+' or '-'). Without %+, positive values have no sign prefix, and negative values have a '-' prefix prepended to them.
Left-justify the output within the specified field width. If the width of the output is less than the specified field width, the output will be padded with blanks on the right-hand side. Without %-, values are right-justified by default.
Zero-fill the output field if the output is right-justified and the width of the output is less than the specified field width. Without %0, right-justified values are prepended with blanks in order to fill the field.