with positive integers you could use .isdigit:
>>> '16'.isdigit()
True
it doesn't work with negative integers though. suppose you could try the following:
>>> s = '-17'
>>> s.startswith('-') and s[1:].isdigit()
True
it won't work with '16.0' format, which is similar to int casting in this sense.
edit:
def check_int(s):
if s[0] in ('-', '+'):
return s[1:].isdigit()
return s.isdigit()
Top answer 1 of 16
1154
with positive integers you could use .isdigit:
>>> '16'.isdigit()
True
it doesn't work with negative integers though. suppose you could try the following:
>>> s = '-17'
>>> s.startswith('-') and s[1:].isdigit()
True
it won't work with '16.0' format, which is similar to int casting in this sense.
edit:
def check_int(s):
if s[0] in ('-', '+'):
return s[1:].isdigit()
return s.isdigit()
2 of 16
517
If you're really just annoyed at using try/excepts all over the place, please just write a helper function:
def represents_int(s):
try:
int(s)
except ValueError:
return False
else:
return True
>>> print(represents_int("+123"))
True
>>> print(represents_int("10.0"))
False
It's going to be WAY more code to exactly cover all the strings that Python considers integers. I say just be pythonic on this one.
GeeksforGeeks
geeksforgeeks.org › python › check-if-string-is-integer-in-python
Check If String is Integer in Python - GeeksforGeeks
July 23, 2025 - In Python, isdigit() is a string method that is used to determine whether the characters of a string are digits or not. So in this method, we are going to use this property to determine whether a given string is an integer value or not.
How to think about integers, strings, and floats?
the difference of integers, strings, and floats integers: whole numbers with no decimal in the value, positive or negative (1, 5000, -4) floats: short for "floating-point number", anything with a decimal point (3.14, 1.0) string: anything text, always surrounded by quotation marks ("word", "3") We've used it for stuff like print(f"You are {age} years old!") Just for clarity's sake, the f there has nothing to do with floats. That's just an F-string for variable interpolation. More on reddit.com
12
1
June 17, 2023Command basics/ python strings vs integers
What is the differences between “1” and 1? Is “1” known as outcome 1 known as input More on discuss.python.org
4
0
October 16, 2023how are you supposed to add an integer to a string?
If what you want is mathematical addition (i.e. you'd want 1 and "2" to add to 3), then yes, you want to convert the string to an int first using int() (or, if it's not actually an integer, to float using float()). If what you want is string concatenation (i.e. you'd want 1 and "2" to add to "12"), then you'll either need to convert the integer to str first or use f strings or the format method etc. More on reddit.com
20
9
March 24, 2024i am a beginner at python and im trying to convert string to int but it doesn't work
What? You can't convert "sadsad" to an int. What would that even mean? Don't you mean you want to convert the integer 170 to a string, instead? More on reddit.com
21
1
August 8, 2023Videos
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Python Validation: How to Check If a String Is an Integer - YouTube
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Python Program to convert String to Integer #shorts - YouTube
Reddit
reddit.com › r/learnpython › how can i check if a string represents an integer?
r/learnpython on Reddit: How can I check if a string represents an integer?
April 7, 2021 -
I tried it with isinstance(<var>, int)
But if the string is: '5', it returns False because it's still a string.
If you write isinstance(int(<var>), int), in some cases it works but when the string is 'abc' the string cannot be casted into an integer and an error pops up. With type() it's the same problem.
With:
try:
int( '7.5')
except:
#code
7.5 can get casted into an integer but it's not an actual integer.
Top answer 1 of 6
8
See the various str methods : if yourvar.isdecimal(): A notable difference to using .isdigit you often see in examples is that also characters like ² are considered a digit (so isdigit() will return True), while it isn't a decimal. Also you're example is not actually true: >>> int('7.5') Traceback (most recent call last): File "", line 1, in ValueError: invalid literal for int() with base 10: '7.5' Because it can't be converted into an int at all, having a non-decimal character. What you're may confusing it with is providing a float to int() as that will simply use the object's integer part, making conversion transparent. That means that for strings you could actually use the try/except as a int-tester too, like in a custom function def is_int(val): try: int(val) return True except ValueError: return False if is_int(yourvar): As a sidenote about 'casting': casting is not in play in Python. Casting means you use the literal byte value(s) in memory in an operation meant for a different datatype. Say you have the ASCII string 'a' stored in memory, which is decimal value 97, then you could use that in a regular calculation to add, say 10 to it, resulting in the value 107. Reading that back as if it's a string, it will print the letter 'k'. In that way, the string variable is cast as an integer to perform the calculation. Without actually dealing with the string content ('a' is meaningless for a calculation like adding 10 to it), it's dealing with the literal 0 and 1 bits of the variable's data. In cases of using data in another representation, like '7' to be the integer 7, you are 'converting' or, specifically for strings, 'parsing' a value.
2 of 6
5
Try converting it to an integer, and catch the exception if it occurs.
Python documentation
docs.python.org › 3 › library › stdtypes.html
Built-in Types — Python 3.14.3 documentation
February 25, 2026 - See also istitle(). ... Return a copy of the string in which each character has been mapped through the given translation table. The table must be an object that implements indexing via __getitem__(), typically a mapping or sequence. When indexed by a Unicode ordinal (an integer), the table object can do any of the following: return a Unicode ordinal or a string, to map the character to one or more other characters; return None, to delete the character from the return string; or raise a LookupError exception, to map the character to itself.
Flexiple
flexiple.com › python › check-if-int-python
How to Check if a String is an Integer in Python? - Flexiple
March 21, 2024 - Use the isdigit() method in Python to check if a string is a number. This method is straightforward and returns True when all characters in the string are digits, and the string is not empty. It's particularly useful for validating positive integers.
FavTutor
favtutor.com › blogs › check-string-is-integer-python
How to Check if the String is Integer in Python
November 28, 2023 - Using the exception-handling approach, we determine whether the "string" is an "integer" or not. This entails "trying" to typecast the string into an integer. If it does not throw any ValueErrors, it is an integer.
DataCamp
datacamp.com › tutorial › how-to-convert-a-string-into-an-integer-in-python
How to Convert a String Into an Integer in Python | DataCamp
November 24, 2024 - Understanding these is crucial for effective programming. Below, is a non-exhaustive list of Python data types: String (str): Textual data enclosed in quotes. E.g., greeting = "Hello, World!" Integer (int): Whole numbers without a fractional component.
Medium
medium.com › @ravi.k7 › python-check-if-string-is-an-integer-or-float-aa122521c99f
Python — Check If String is an Integer or Float | by Handan | Medium
December 24, 2022 - You can use the isdigit method of the String class to check if the given string input is a number or not. Suppose if the given input is not a number in that case this method will return false and hence based on the return of this method you ...
Educative
educative.io › answers › how-to-check-if-a-string-contains-integers-in-python
How to check if a string contains integers in Python
Multiple custom logics can be made for checking whether a string contains an integers or not. In this Answer, we’ll learn how we can use the basic Python functions, the isdigit() and isdecimal(), to check if a string contains integers or not.
Python documentation
docs.python.org › 3 › reference › lexical_analysis.html
2. Lexical analysis — Python 3.14.3 documentation
February 23, 2026 - Note that not all valid inputs ... an expression composed of the unary operator ‘-’ and the literal 1. Integer literals denote whole numbers....
Automate the Boring Stuff
automatetheboringstuff.com › 3e › chapter1.html
Chapter 1 - Python Basics, Automate the Boring Stuff with Python, 3rd Ed
It is then passed to print() to be displayed on the screen. The print() function allows you to pass it either integer values or string values, but notice the error that shows up when you enter the following into the interactive shell: >>> print('I am ' + 29 + ' years old.') Traceback (most recent call last): File "<python-input-0>", line 1, in <module> print('I am ' + 29 + ' years old.') TypeError: can only concatenate str (not "int") to str
LeetCode
leetcode.com › problems › string-to-integer-atoi
String to Integer (atoi) - LeetCode
Can you solve this real interview question? String to Integer (atoi) - Implement the myAtoi(string s) function, which converts a string to a 32-bit signed integer. The algorithm for myAtoi(string s) is as follows: 1. Whitespace: Ignore any leading ...
Vultr Docs
docs.vultr.com › python › built-in › int
Python int() - Convert Value to Integer | Vultr Docs
November 22, 2024 - This converts the binary string '1010' to the decimal integer 10. The second parameter in int() specifies that the number is in base 2.
W3Schools
w3schools.com › python › ref_string_isdigit.asp
Python String isdigit() Method
Remove List Duplicates Reverse ... Bootcamp Python Certificate Python Training ... The isdigit() method returns True if all the characters are digits, otherwise False....
Python documentation
docs.python.org › 3 › library › functions.html
Built-in Functions — Python 3.14.3 documentation
February 27, 2026 - This function is added to the built-in namespace by the site module. Changed in version 3.4: Changes to pydoc and inspect mean that the reported signatures for callables are now more comprehensive and consistent. ... Convert an integer number to a lowercase hexadecimal string prefixed with “0x”. If integer is not a Python int object, it has to define an __index__() method that returns an integer.
Safe Community
community.safe.com › home › forums › fme form › authoring › string value to integer in python
String Value to integer in Python | Community
January 19, 2016 - As david_r already mentioned, it is important to use the round function when converting from a float towards an integer. Below I also implemented a try-except block to show a warning in the log if the conversion fails. import fme import fmeobjects logger = fmeobjects.FMELogFile() # Template Function interface: def convertToInteger(feature): string = feature.getAttribute('string') try: integer = float(string) integer = round(integer) integer = int(integer) feature.setAttribute('integer', integer) except: logger.logMessageString('The following string couldn\'t be converted towards an integer: %s.' % (string), fmeobjects.FME_WARN)
GeeksforGeeks
geeksforgeeks.org › python › python-check-if-given-string-is-numeric-or-not
Python Check If String is Number - GeeksforGeeks
July 11, 2025 - This approach involves checking if a string is a number in Python using a "try" and "except" block, you can try to convert the string to a numeric type (e.g., int or float) using the relevant conversion functions. If the conversion is successful without raising an exception, it indicates that the string is a valid number. Example : In this example the below code checks if a given string can be converted to an integer using the `int()` function.
Reddit
reddit.com › r/learnpython › how to think about integers, strings, and floats?
r/learnpython on Reddit: How to think about integers, strings, and floats?
June 17, 2023 -
So I am taking a intro to python class right now, I'm doing well in it and everything, but I guess I was asleep when they showed the slide telling the difference of integers, strings, and floats lol
I've never been "stuck" with anything because of it, and I am pretty good with excel so I understand stuff with VALUE() being necessary sometimes, as numbers (integers) can be stored as a string. I guess I just don't really know what float means. We've used it for stuff like
print(f"You are {age} years old!")
So I get that adding the f makes python know you are wanting to use that variable reference thing
What's a float?
Top answer 1 of 7
10
the difference of integers, strings, and floats integers: whole numbers with no decimal in the value, positive or negative (1, 5000, -4) floats: short for "floating-point number", anything with a decimal point (3.14, 1.0) string: anything text, always surrounded by quotation marks ("word", "3") We've used it for stuff like print(f"You are {age} years old!") Just for clarity's sake, the f there has nothing to do with floats. That's just an F-string for variable interpolation.
2 of 7
2
decimals ex. 5.5
Top answer 1 of 4
2
Hey there, … the difference I see there is just their data types , one is a string and the other an integer… or what differences did you have in mind?
2 of 4
0
Thanks so much Kyle. I’m just a beginner and just learning the basis. Can you send any link to me that can improve my knowledge in python. Cheers!
Reddit
reddit.com › r/learnpython › how are you supposed to add an integer to a string?
r/learnpython on Reddit: how are you supposed to add an integer to a string?
March 24, 2024 -
im new to python and trying to learn how to print the sum of a integer and a string number, i get an error that says| unsupported operand type(s) +: 'int' and 'str' | i dont know how to solve it and everything i look up only has for int + int so im wondering if i have to just convert the string to a integer and if so how would that be done but if thats not what i need to do i would also really appreciate an explanation.
Top answer 1 of 5
18
If what you want is mathematical addition (i.e. you'd want 1 and "2" to add to 3), then yes, you want to convert the string to an int first using int() (or, if it's not actually an integer, to float using float()). If what you want is string concatenation (i.e. you'd want 1 and "2" to add to "12"), then you'll either need to convert the integer to str first or use f strings or the format method etc.
2 of 5
15
if i have to just convert the string to a integer Yep, you nailed it. result = myint + int(mystr)