How to use pprint to print an object using the built-in __str__(self) method?

Question

I have a Python script which processes a .txt file which contains report usage information. I\'d like to find a way to cleanly print the attributes of an object using pprint\'s

Answer 1

pprint is just another form of print. When you say pprint(vars(self)) it prints vars into stdout and returns none because it is a void function. So when you cast it to a string it turns None (returned by pprint) into a string which is then printed from the initial print statement. I would suggest changing your print to pprint or redefine print as print if its all you use it for.

def __str__(self):
    from pprint import pprint
    return str(vars(self))

for i,line in enumerate(open(path+file_1,'r')):
    line = line.strip().split("|")
    if i == 0:
        headers = line
    if i == 1:
        record = Report(line,headers)
        pprint record

One alternative is to use a formatted output:

def __str__(self):
    return "date added:   %s\nPrice:        %s\nReport:       %s\nretail price: %s\nuser:         %s" % tuple([str(i) for i in vars(self).values()])

Hope this helped