Although it is a memorandum for myself to learn Python, here is a summary of how to read error messages.
I would like to take this opportunity to thank you for solving the problem by borrowing the wisdom of our predecessors, and I am very sorry to say that I will summarize it here as my own memo.
1-1.
--Caused by miss typing. It also happens with the difference between uppercase and lowercase letters.
python
prlnt("Hello World !") #Wrong...print→prlnt
print("Hello World !") #Positive
Terminal
Traceback (most resent call last):
file "c:/～/sample.py", line 1, in <module>
pilnt("Hello World !")
NameError: name 'Pilnt' is not defined
[Translation] Name error in module in last last call: The name "pilnt" on the first line is undefined. ↓ ** "I made a misspelling! 』** That means.
1-2.
--Occurs when a function call is made before the function definition.
python
print(cost(100000)) #Wrong...Calling cost before definition
def cost(bill):
return int(bill * 1.1)
Terminal
NameError: name 'cost' id not defined
[Translation] Name error occurred: "cost" is not defined. ↓ ** "I haven't figured out or understood the function" cost "yet" **.
――It happens due to a mistake in grammar.
2-1.
python
print("Hello World !) #Wrong...Forget closing quotes
print("Hello World !") #Positive
Terminal
SyntaxError: EOL while scaning stringliteral
[Translation] A syntax error occurred: An End Of Line was found while scanning a string literal. ↓ ** "I thought it was a character string, but it ended up at the end of the line! ?? Fine? 』** That means.
2-2.
python
print( Hello World ! ) #Wrong...Forget quotes
print("Hello World !") #Positive
Terminal
SyntaxError: invalid character in identifier
[Translation] A syntax error has occurred: An invalid character was found in the identifier. ↓ ** "I thought it was a variable or a function (because it's not enclosed in quotes), but don't use"! "~" **.
Note
The "!" (Exclamation mark) is a character that cannot be used as the name of a variable or function. For this reason, it has been pointed out as an illegal character.
2-3.
python
ifheight > 180: #Wrong...There is no half-width space immediately after if
if height > 180: #Positive
Terminal
SyntaxError: invalid systax
[Translation] Grammar error occurred: Illegal grammar. ↓ ** "You can't write like that" **.
--Occurs when there is a problem with the data type.
python
print(5 + "Sheet") #Wrong...5(Numerical value)When,"Sheet"(String)I tried to combine with the + operator, but I can't concatenate because they are different.
print("5" + "Sheet") #Positive...Match the type to the str type
print(str(5) + "Sheet") #Positive...Same as above
Terminal
TypeError: unsupporter operand type(s) for +: 'int' and 'str'
[Translation] Type error occurs: The + operator does not support the type of the operand. ↓ ** "Since the data type is different between int and str, we can't process them together" **.
--This happens when there is no nested indentation for if, for statement, function, etc., or when there is a gap.
python
if counter > 10:
break #Wrong...No indentation
if counter > 10:
break #Positive
Terminal
IndentationError: expected an indented block
[Translation] Indent error occurs: Predicts that an indented block is needed. ↓ ** "I haven't indented, but I need indentation ~" **.
--This happens when a character string containing non-numeric characters is used as an argument of the int function.
--Occurs when an unsupported data type is passed to a function.
Terminal
ValueError: invalid literal for int() with base 10: 'xxxxxxx'
[Translation] Value error occurred: Illegal literal: string "xxxxxxx" for int function with argument base 10. ↓ ** "I'm putting a character string to convert in decimal! 』** That means.
--Occurs when the module cannot be imported. (Mainly due to typos)
python
import xxxxxxxx
Terminal
ModuleNotFoundError: No module named 'xxxxxxxx' #I can't find the module name "xxxxxxxx"
[Translation] Module not found error occurred: There is no module named "xxxxxxxx". ↓ ** "There is no module named" xxxxxxxx "! 』** That means.
--What happens when you divide by so-called "zero"
python
10 + 10 + 10 + 10 * 0 + 10 + 10 / 0 + 10
Terminal
ZeroDivisionError: division by zero
[Translation] Zero division error occurred: Divided by zero. ↓ (As it is) ** "It's a zero split! 』** That means.
--It happens when you stop the infinite loop by pressing "ctrl" + "C" keys.
Terminal
Traceback (most resent call last):
file "c:/～/sample.py", line 120, in <module>
counter += 1
KeyboardInterruput
[Translation] I got an interrupt from the keyboard. ↓ ** "I stopped the program by inputting an interrupt from the keyboard! 』** That means.
I have collected and summarized the errors that I often encounter. First of all, I want to understand the content, cause and reason of a simple error so that I will not panic when an error occurs when programming complicatedly.
VS Code seems to have an extension that checks the grammar in real time, so I'll try various things.
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