试图调整，居中和调整秒表的输出

Question

I have a stopwatch program that is fully functional. All I am trying to do is format the output to be aligned.

This was a section of the code before trying to edit:

 lapTime = round(time.time() - lastTime, 2)
 totalTime = round(time.time() - startTime, 2)
 print ('Lap #%s: %s (%s)' % (lapNum, totalTime, lapTime), end='')

This was one of the attempts to align the output:

 print ('Lap ', lapNum.ljust(10, ' ')), ':',totalTime.center(20, ' '), 
 lapTime.rjust(30, ' '))

I am getting the error:

 File "D:/stopwatch2.py", line 19, in main
     print ('Lap ' + str(lapNum.ljust(10, ' ')), ':',totalTime.center(40, 
 ' '), lapTime.rjust(50, ' '))
 AttributeError: 'int' object has no attribute 'ljust'

Answer 1

ljust and center are string methods. You have to convert the value to strings before you call those methods:

print ('Lap ', str(lapNum).ljust(10, ' '), ':', str(totalTime).center(20, ' '))

You can also use str.format and the format options :

print ('Lap {:<10}: {:=20}'.format(lapNum, totalTime))
# output: Lap 1         :           1557332386

With str.format the conversion to a string is implicit.