Some problems that you may have encountered in working with Python:

• __str__ and __repr__ methods: There are two forms of the "toString" method in Python. The first is __str__ which returns a string representation of an object. This is the method that is called when you do "print obj". The __repr__ method returns the "official" string represntation of the object. The __repr__ method is called when the object is put in backquotes. The idea is that the string produced by __repr__ should be a vaild Python expression that could be used to reconstruct the object. You probably have already noticed the differences between __str__ and __repr__ when you did Part 2 of e03.
• Printing numbers to k decimal places: Python uses the same format strings as C, and then defines a % operator to translate variables given the format strings. So, for example, the following prints a floating point number x to 4 decimal places: print "the value of x is %.4f" % x. The formatting information in the string is %.4f where the f means that we expect to format a floating point number, the .4 means display 4 decimal places.