coding-mentor-agent/kb/python-course-kb-practical-python/wiki/exercises/1-6-debugging.md

id, source_exercise_id, title, section, source_path, source_repo, source_commit, student_visible_solution, has_private_solution, skip

id	source_exercise_id	title	section	source_path	source_repo	source_commit	student_visible_solution	has_private_solution	skip
practical-python-1.6	1.6	Debugging	1.2 A First Program	01_Introduction/02_Hello_world.md	https://github.com/dabeaz-course/practical-python	93dca856b41c61a0a0f85ae334116e4c125629ea	false	false	false

Exercise 1.6: Debugging

Source: Practical Python Programming, 01_Introduction/02_Hello_world.md.

Exercise 1.6: Debugging

The following code fragment contains code from the Sears tower problem. It also has a bug in it.

# sears.py

bill_thickness = 0.11 * 0.001    # Meters (0.11 mm)
sears_height   = 442             # Height (meters)
num_bills      = 1
day            = 1

while num_bills * bill_thickness < sears_height:
    print(day, num_bills, num_bills * bill_thickness)
    day = days + 1
    num_bills = num_bills * 2

print('Number of days', day)
print('Number of bills', num_bills)
print('Final height', num_bills * bill_thickness)

Copy and paste the code that appears above in a new program called sears.py. When you run the code you will get an error message that causes the program to crash like this:

Traceback (most recent call last):
  File "sears.py", line 10, in <module>
    day = days + 1
NameError: name 'days' is not defined

Reading error messages is an important part of Python code. If your program crashes, the very last line of the traceback message is the actual reason why the the program crashed. Above that, you should see a fragment of source code and then an identifying filename and line number.

• Which line is the error?
• What is the error?
• Fix the error
• Run the program successfully

Contents | Previous (1.1 Python) | Next (1.3 Numbers)

关联来源

• summaries/02_Hello_world