So this is probably a very basic question about output formatting in python using '.format' and since I'm a beginner, I can't figure this out for the life of me. I've tried to be as detailed as possible, just to make sure that there's no confusion.
Let me give you an example so that you can better understand my dilemma. Consider the following program
list = (['wer', 'werwe', 'werwe' ,'wer we']) # list[0], list[1], list[2], list[3]
list.append(['vbcv', 'cvnc', 'bnfhn', 'mjyh']) # list[4]
list.append(['yth', 'rnhn', 'mjyu', 'mujym']) # list[5]
list.append(['cxzz', 'bncz', 'nhrt', 'qweq']) # list[6]
first = 'bill'
last = 'gates'
print ('{:10} {:10} {:10} {:10}'.format(first,last,list[5], list[6]))
Understandably that would give the output:
bill gates ['yth', 'rnhn', 'mjyu', 'mujym'] ['cxzz', 'bncz', 'nhrt', 'qweq']
So here's my real question. I was doing this practice problem from the book and I don't understand the answer. The program below will give you a good idea of what kind of output we are going for:
students = []
students.append(['DeMoines', 'Jim', 'Sophomore', 3.45]) #students[0]
students.append(['Pierre', 'Sophie', 'Sophomore', 4.0]) #students[1]
students.append(['Columbus', 'Maria', 'Senior', 2.5]) #students[2]
students.append(['Phoenix', 'River', 'Junior', 2.45]) #students[3]
students.append(['Olympis', 'Edgar', 'Junior', 3.99]) #students[4]
students.append(['van','john', 'junior', 3.56]) #students[5]
def Grades(students):
print ('Last First Standing GPA')
for students in students:
print('{0:10} {1:10} {2:10} {3:8.2f}'.format(students[0],students[1],students[2],students[3]))
The output we're trying to get is a kind of a table that gives all the stats for all the students -
Last First Standing GPA
DeMoines Jim Sophomore 3.45
Pierre Sophie Sophomore 4.00
Columbus Maria Senior 2.50
Phoenix River Junior 2.45
Olympis Edgar Junior 3.99
van john junior 3.56
So here's what I don't understand. We are working with basically the same thing in the two examples i.e. a list inside a list. For my first example, the print statement was:
print('{:10} {:10} {:10} {:10}'.format(first, last, list[5], list[6]))
where list[5] and list[6] are lists themselves and they are printed in entirety, as you can see from the output. But that doesn't happen in the book problem. There, the print statement says
print('{0:10} {1:10} {2:10} {3:8.2f}'.format(students[0], students[1], students[2], students[3]))
As you can see from the table output, here students[0] refers only to 'DeMoines'. But if you just run the statement students[0] in the Python interpreter, it gives the whole sub list, as it should.
['DeMoines', 'Jim', 'Sophomore', 3.45]
So, basically, I've got two questions, why does students[0] have two different meanings and why does students[0] not print the whole list like we did with list[5] and list[6]?
Look at the for loop:
for students in students:
# ^^^^^^^^
So, students(inside loop) does not actually refers to list of list. And students[0] refers to first element from element from list of lists, as expected.
I suggest replace students from function argument, say, with all_students or something like that.