I’m a newbie to Python and currently learning Control Flow commands like if
, else
, etc.
The if
statement is working all fine, but when I write else
or elif
commands, the interpreter gives me a syntax error. I’m using Python 3.2.1 and the problem is arising in both its native interpreter and IDLE.
I’m following as it is given in the book ‘A Byte Of Python’ . As you can see, elif
and else
are giving Invalid Syntax.
>> number=23
>> guess = input('Enter a number : ')
>> if guess == number:
>> print('Congratulations! You guessed it.')
>> elif guess < number:
**( It is giving me 'Invalid Syntax')**
>> else:
**( It is also giving me 'Invalid syntax')**
Why is this happening? I’m getting the problem in both IDLE and the interactive python. I hope the syntax is right.
Brad Koch
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asked Aug 11, 2011 at 11:59
4
It looks like you are entering a blank line after the body of the if
statement. This is a cue to the interactive compiler that you are done with the block entirely, so it is not expecting any elif
/else
blocks. Try entering the code exactly like this, and only hit enter once after each line:
if guess == number:
print('Congratulations! You guessed it.')
elif guess < number:
pass # Your code here
else:
pass # Your code here
answered Aug 11, 2011 at 12:08
cdhowiecdhowie
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The problem is the blank line you are typing before the else
or elif
. Pay attention to the prompt you’re given. If it is >>>
, then Python is expecting the start of a new statement. If it is ...
, then it’s expecting you to continue a previous statement.
answered Aug 11, 2011 at 12:08
Ned BatchelderNed Batchelder
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elif
and else
must immediately follow the end of the if
block, or Python will assume that the block has closed without them.
if 1:
pass
<--- this line must be indented at the same level as the `pass`
else:
pass
In your code, the interpreter finishes the if
block when the indentation, so the elif
and the else
aren’t associated with it. They are thus being understood as standalone statements, which doesn’t make sense.
In general, try to follow the style guidelines, which include removing excessive whitespace.
answered Aug 11, 2011 at 12:04
KatrielKatriel
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In IDLE and the interactive python, you entered two consecutive CRLF which brings you out of the if statement.
It’s the problem of IDLE or interactive python. It will be ok when you using any kind of editor, just make sure your indentation is right.
answered Aug 11, 2011 at 14:08
MengMeng
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if guess == number:
print ("Good")
elif guess == 2:
print ("Bad")
else:
print ("Also bad")
Make sure you have your identation right. The syntax is ok.
paxdiablo
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answered Aug 11, 2011 at 12:04
BogdanBogdan
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Remember that by default the return value from the input will be a string and not an integer. You cannot compare strings with booleans like <, >, =>, <= (unless you are comparing the length). Therefore your code should look like this:
number = 23
guess = int(input('Enter a number: ')) # The var guess will be an integer
if guess == number:
print('Congratulations! You guessed it.')
elif guess != number:
print('Wrong Number')
answered Feb 15, 2017 at 2:42
NelloNello
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Besides that your indention is wrong. The code wont work.
I know you are using python 3. something.
I am using python 2.7.3
the code that will actually work for what you trying accomplish is this.
number = str(23)
guess = input('Enter a number: ')
if guess == number:
print('Congratulations! You guessed it.')
elif guess < number:
print('Wrong Number')
elif guess < number:
print("Wrong Number')
The only difference I would tell python that number is a string of character for the code to work. If not is going to think is a Integer. When somebody runs the code they are inputing a string not an integer. There are many ways of changing this code but this is the easy solution I wanted to provide there is another way that I cant think of without making the 23 into a string. Or you could of «23» put quotations or you could of use int() function in the input. that would transform anything they input into and integer a number.
answered Apr 12, 2013 at 21:39
NOE2270667NOE2270667
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Python can generate same ‘invalid syntax’ error even if ident for ‘elif’ block not matching to ‘if’ block ident (tabs for the first, spaces for second or vice versa).
answered May 14, 2017 at 3:29
AlfisheAlfishe
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indentation is important in Python. Your if else statement should be within triple arrow (>>>), In Mac python IDLE version 3.7.4 elif statement doesn’t comes with correct indentation when you go on next line you have to shift left to avoid syntax error.
answered Jul 29, 2019 at 2:07
bikram sapkotabikram sapkota
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number = 23
guess = int(input('Введите целое число : '))
if guess == number :
print('Поздравляю, вы угадали, ') #Начало нового блока
print('хотя и не выиграли никакого приза!)') #Конец нового блока
elif guess < number :
print('Нет, загаданное число немного больше этого.') #Ещё один блок
#Внутри блока, вы можете выполнять всё, что угодно...
else
print('Нет, загаданное число немного меньше этого.')
#Чтобы попасть сюда guess должно быть больше, чем number
print('Завершено')
Текст ошибки:
File «C:UsersUserDesktopPythonif.py», line 6
elif guess < number :
^
SyntaxError: invalid syntax
Что не так?
-
Вопрос заданболее двух лет назад
-
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Отступы при таких операторах должны быть одинаковыми:
if cond:
...
elif cond:
...
else:
...
Пригласить эксперта
number = 23
guess = int(input('Введите целое число : '))
if guess == number :
print('Поздравляю, вы угадали, ') #Начало нового блока
print('хотя и не выиграли никакого приза!)') #Конец нового блока
elif guess < number :
print('Нет, загаданное число немного больше этого.') #Ещё один блок
#Внутри блока, вы можете выполнять всё, что угодно...
else:
print('Нет, загаданное число немного меньше этого.')
#Чтобы попасть сюда guess должно быть больше, чем number
print('Завершено')
-
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Минуточку внимания
Nothing is more frustrating than encountering a syntax error when you think your code is perfect. In this article, we’re going to dissect the ‘elif’ function in Python, unraveling common syntax errors and their solutions.
In this article we shall deep dive into a particular function exploring the different potential syntax errors that might pop-up while running it. So, with no further ado, let’s dive into debunking the syntax errors in the ‘elif’ function in Python.
- The Indentation Oversight
- Using Incorrect Operators
- The Missing Parenthesis
Also read: Python if else elif Statement
Common ‘elif’ syntax errors in Python include indentation errors, misuse of operators, and missing parentheses. Correcting these errors involves placing ‘if’ and ‘elif’ at the same indent level, using ‘==’ for comparison instead of ‘=’, and ensuring that all parentheses are properly closed. These corrections help to maintain the flow of code execution and prevent syntax errors.
Elif Syntax Error 1: Indentation Oversight
Indents play a crucial role while constructing conditional statements in Python coding. Indentation conveys the relationship between a condition and its subsequent instructions. Let us have a look at the below example to witness how things could derail so swiftly.
ip = int(input("Enter your year of birth:")) if ip>2000: print("Welcome 2k kid!") elif ip<2000: print("Wow you’re old!")
It can be seen that the code was not even completed, but there is a syntax error knocking right at the door! Wonder what went wrong? The indentation! Here, ‘elif’ is indented at the same level as the statements within the ‘if’ block, which is a mistake.
This raises a conflict when the set of instructions following the if are run since elif is also taken for execution but in actual case, it needn’t be. So the solution here is to place both the if and the elif at the same indent such as in the code given below.
if ip>2000: print("Welcome 2k kid!") elif ip<2000: print("Wow you’re old!")
Elif Syntax Error 2 – Using Incorrect Operators
Sometimes, a subtle difference in operator usage can lead to syntax errors in an ‘elif’ statement. Let us have a look at how this happens.
The comparison turmoil: Oftentimes one shall use “=” synonymous with “==”, but these two are really distinct and do not serve the same purpose. The former is used to assign a value whilst the latter is used to compare values. There is no point in assigning a value following the if, rather one only needs to compare a value in that place. When this incorrect synonymy enters into an elif code, it is a sure shot recipe for a syntax error. The below example shall explain better.
Python is smart enough to suggest that the coder might want to use “==” in the place of “=” when encountering a “=” in an if code. Nice, ain’t it?
Let us now correct it and get on with the code to see what happens.
The missing colon: What? Again? But this time it’s for a different reason. There is a missing ‘:’ following the elif that has caused the syntax error. Rectifying this should make the code work.
Elif Syntax Error 3 – The Missing Parenthesis
While it may seem trivial, missing parentheses can cause serious syntax issues. Sometimes, one can forget to finish what was started (i.e) close those brackets which were opened. Take a look at the code below for a better understanding.
After adding the missing parenthesis, the code executes flawlessly.
ip = 5675 if int(ip == 5675): print("True") elif int(ip !=5675): print("False")
Conclusion
This article has taken you on a journey through the common syntax errors encountered when using Python’s ‘elif’ function. With this knowledge, you should be able to debug such issues more efficiently. Here’s another article that details the usage of bit manipulation and bit masking in Python. There are numerous other enjoyable and equally informative articles in AskPython that might be of great help to those who are looking to level up in Python. Audere est facere!
Reference:
- https://docs.python.org/3/tutorial/controlflow.html
You can combine the else
statement with the elif
and if
statements in Python. But when running if...elif...else
statements in your code, you might get an error named SyntaxError: invalid syntax
in Python.
It mainly occurs when there is a wrong indentation in the code. This tutorial will teach you to fix SyntaxError: invalid syntax
in Python.
Fix the else
& elif
Statements SyntaxError
in Python
Indentation is the leading whitespace (spaces and tabs) in a code line in Python. Unlike other programming languages, indentation is very important in Python.
Python uses indentation to represent a block of code. When the indentation is not done properly, it will give you an error.
Let us see an example of else
and elif
statements.
Code Example:
num=25
guess=int(input("Guess the number:"))
if guess == num:
print("correct")
elif guess < num:
print("The number is greater.")
else:
print("The number is smaller.")
Error Output:
File "c:Usersrhntmmyscript.py", line 5
elif guess < num:
^^^^
SyntaxError: invalid syntax
The above example raises an exception, SyntaxError
, because the indentation is not followed correctly in line 5. You must use the else
code block after the if
code block.
The elif
statement needs to be in line with the if
statement, as shown below.
Code Example:
num=25
guess=int(input("Guess the number:"))
if guess == num:
print("correct")
elif guess < num:
print("The number is greater.")
else:
print("The number is smaller.")
Output:
Guess the number:20
The number is greater.
Now, the code runs successfully.
The indentation is essential in Python for structuring the code block of a statement. The number of spaces in a group of statements must be equal to indicate a block of code.
The default indentation is 4 spaces in Python. It is up to you, but at least one space has to be used.
If there is a wrong indentation in the code, you will get an IndentationError
in Python. You can fix it by correcting the indent in your code.
i’m having an invalid syntax on my elif statements why heres the code:
while correct_turns != len(word):
if correct_turns == len(word):
finish()
guess = input("Please guess a letter from above: ")
elif guess in word and not LettersUnused:
used_letter(guess,display,LettersUnused)
elif guess in word and LettersUnused:
correct(guess,display,correct_turns,LettersUnused)
elif guess in LettersUnused and not word:
incorrect(guess,display,LettersUnused)
elif guess not in LettersUnused:
used_letter(guess,display,LettersUnused)
elif len(guess)>1:
guess_word(guess)
jonrsharpe
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asked Apr 21, 2014 at 14:00
1
Your first elif
should just be an if
, given your indentation. The elif
s aren’t really related to the first if
anyway.
answered Apr 21, 2014 at 14:05
chepnerchepner
492k70 gold badges517 silver badges674 bronze badges
You don’t need the initial if
, because your while
loop conditional prevents the loop from being entered.
You cannot otherwise ‘continue’ an if
block with another line in between. Change the first elif
into an if
to start a new block; you may as well remove the other if
statement as it’ll never execute.
while correct_turns != len(word):
guess = input("Please guess a letter from above: ")
if guess in word and not LettersUnused:
used_letter(guess,display,LettersUnused)
elif guess in word and LettersUnused:
correct(guess,display,correct_turns,LettersUnused)
elif guess in LettersUnused and not word:
incorrect(guess,display,LettersUnused)
elif guess not in LettersUnused:
used_letter(guess,display,LettersUnused)
elif len(guess)>1:
guess_word(guess)
answered Apr 21, 2014 at 14:08
Martijn Pieters♦Martijn Pieters
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3