WEBVTT 00:00.630 --> 00:05.880 Every programmer makes mistakes and most make mistakes every day. 00:06.300 --> 00:13.920 Although good programmers might create errors and they also know how to respond to these errors efficiently. 00:14.100 --> 00:20.640 Now let's look at an error you will likely to make early on and learn how to fix it. 00:20.670 --> 00:28.800 So we will write some code that generates an error on purpose and enter the this code here. 00:29.340 --> 00:30.090 Message. 00:31.630 --> 00:35.080 Message here and we will write. 00:35.410 --> 00:35.950 Hello. 00:38.180 --> 00:38.990 By then. 00:39.470 --> 00:40.190 Parash. 00:41.380 --> 00:42.190 Or Python. 00:45.940 --> 00:49.180 After that, we will print message. 00:52.390 --> 00:58.870 So if an error occurs in your program, the Python interpreter does its best to help you figure out 00:58.870 --> 01:00.550 where the problem is. 01:02.840 --> 01:09.140 So the interpreter provides a traceback when a program cannot run successfully. 01:09.410 --> 01:09.980 Here. 01:10.220 --> 01:11.060 That's it. 01:12.040 --> 01:14.140 It's actually widen it a little bit. 01:17.500 --> 01:25.570 The traceback is a record of where the interpreter ran into trouble when trying to execute your code. 01:26.390 --> 01:33.320 Here's an example of the traceback that Python provides after you have accidentally misspelled a variable's 01:33.320 --> 01:33.890 name. 01:34.850 --> 01:35.510 Here. 01:35.690 --> 01:37.820 Let's actually use this marker. 01:37.820 --> 01:38.390 Yes. 01:39.040 --> 01:41.470 So here, this is our first line, right? 01:41.740 --> 01:44.770 This is our first line that Python gave us. 01:45.190 --> 01:48.460 So here we have error. 01:49.830 --> 01:55.830 And we also have print function names and name message is not defined. 01:56.670 --> 01:58.110 So here. 01:59.380 --> 02:04.900 The output reports that an error occurs in line two. 02:05.890 --> 02:06.370 Here. 02:06.490 --> 02:12.010 Error occurs in line two of the main dot pi. 02:13.780 --> 02:17.620 Python file and the interpreter shows this line. 02:20.800 --> 02:26.470 To help us to stop the error quickly and tells us what kind of error it found. 02:26.860 --> 02:34.810 In this case, it found the name error and reports that the variable being printed message has not been 02:34.810 --> 02:39.970 defined and Python cannot identify the variable name provided. 02:40.330 --> 02:46.960 A name error usually means we either forgot to set a variable's value before using it or we made a spelling 02:46.960 --> 02:50.050 mistake when entering the variables name. 02:50.440 --> 02:59.380 If Python finds a variable name that's similar to one it doesn't recognize, it will ask if that's the 02:59.380 --> 03:01.210 name you meant to use. 03:01.360 --> 03:08.440 In this example we omitted the letter s in the variable name message in the second line and the python 03:08.440 --> 03:14.500 interpreter doesn't spell check your code, but it does ensure that the variable names are spelled consistently. 03:15.400 --> 03:21.490 So, for example, watch what happens when we spell the message incorrectly in the line that defines 03:21.490 --> 03:22.530 the variable. 03:22.540 --> 03:23.830 Let's actually make this. 03:25.150 --> 03:25.960 That's it. 03:25.960 --> 03:30.850 In this case, the program runs successfully the variable name match. 03:30.850 --> 03:38.380 So Python sees no easy programming language are very strict, but they disregard good and bad spelling. 03:38.380 --> 03:44.020 As a result, you don't need to consider English spelling and grammar rules when you are trying to create 03:44.020 --> 03:45.820 a variable names and writing code. 03:45.880 --> 03:52.840 So many programming errors are simple single character typos in one line of program. 03:52.840 --> 03:59.860 If you find yourself spending a lot of time searching for one of these errors, know that you are in 03:59.860 --> 04:00.700 a good company. 04:01.380 --> 04:09.600 So many experienced and talented programmers spent hours hunting down these kinds of tiny errors. 04:09.630 --> 04:17.130 Try to laugh about it and move on, knowing it will happen frequently throughout your programming live.