Syntax Errors-English.txt

 

There are three broad types of errors that you will encounter as a

computer programmer and today we'll talk about the syntax error. Syntax

errors are usually the easiest to deal with. Python and really all

programming languages are very strict. If things aren't typed in exactly

right, Python is not able to guess what you intend to do. For example as a

human I can look at this string and understand that you want "Please enter

your favorite number" to be inside the string. But if I try to run this

program, Python gives me an error because it looks at this single quote at

the beginning of the string and scan's along to try to find another single

quote at the end of the string to tell it that the string is complete. But

it never finds one. And Python doesn't know that this double quote was

intended to mark the end of the string. So we'll change the beginning

single quote to a double quote. Of course we could have also changed the

double quote to a single quote. And this line is OK. I've got another

problem in my program and if I don't see it right away I can scan over to

the right of the edit window. And hover over this red dash. Often the

error messages aren't very helpful, but at least we can identify where the

error is. In this case we used a semicolon instead of a comma to separate

the arguments in this print function. Another way to find the location of

an error is to go ahead and run the program.

Come down to the error in the run, and click on the hyperlink. And that

takes you to the line where the error occurred. Sometimes you'll see

multiple hyperlinks for one error. Often it helps to click on the last

hyperlink first and then work your way up. When we changed the semicolon

to a comma the error disappears in the edit window and we get our green

check. Running the program shows no problem. Notice that I snuck another

little error in here. I changed the word mean m a i n to main m e i n. But

Python will let me name function's whatever I want. So as long as the

function call down here matches the name of the function up here I won't

get an error. I'd want to fix that anyway.