Hello everyone,
I have a very simple question.
Let's say you have a list:
'1 1.5 4.56 32'
And you want to separate the integers from the floats into different lists.
E.G.
int_list=[1,32] float_list=[1.5,4.56]
I've tried a variety of things (convert it to a list and use try/except with int, but this only works with the integers, not the floats). Regex (\d+(?!\.)(?<!\.) basically, a digit that doesn't have a decimal before/after it, but this wouldn't work for the numbers past the 2nd decimal point). Only thing I've found is converting the string to an array and using as.type, but I want to do this without using numpy.
Any help would be greatly appreciated!
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.
Videos
Hello! I recently decided to pick up python 2.7 for a project in my computer science class, but my area has been quarantined by covid-19 and I'm unable to ask my teacher for any help. I'm making a basic unit-conversion calculator, and I'd like to be able to tell what a user is inputting, without changing it. For example, if they put in a string, it would display a message such as "Sorry, only numbers are allowed" and allows the user to try again. I'm using the raw_input() function to get the input, but idk how to discern strings, floats, and integers.
For non-negative (unsigned) integers only, use isdigit():
>>> a = "03523"
>>> a.isdigit()
True
>>> b = "963spam"
>>> b.isdigit()
False
Documentation for isdigit(): Python2, Python3
For Python 2 Unicode strings:
isnumeric().
Which, not only is ugly and slow
I'd dispute both.
A regex or other string parsing method would be uglier and slower.
I'm not sure that anything much could be faster than the above. It calls the function and returns. Try/except doesn't introduce much overhead because the most common exception is caught without an extensive search of stack frames.
The issue across programming languages is that any numeric conversion function has two kinds of results:
- A number, if the number is valid;
- A status code (e.g., via errno) or exception to show that no valid number could be parsed.
C (as an example) hacks around this a number of ways. Python lays it out clearly and explicitly.
I think your code for doing this is just fine. The only thing that could be cleaner is moving the return True into an else block, to be clear that it's not part of the code under test – not that there's much ambiguity.
def is_number(s):
try:
float(s)
except ValueError: # Failed
return False
else: # Succeeded
return True
If the string is convertable to integer, it should be digits only. It should be noted that this approach, as @cwallenpoole said, does NOT work with negative inputs beacuse of the '-' character. You could do:
if NumberString.isdigit():
Number = int(NumberString)
else:
Number = float(NumberString)
If you already have Number confirmed as a float, you can always use is_integer (works with negatives):
if Number.is_integer():
Number = int(Number)
Here is the method to check,
a = '10'
if a.isdigit():
print "Yes it is Integer"
elif a.replace('.','',1).isdigit() and a.count('.') < 2:
print "Its Float"
else:
print "Its is Neither Integer Nor Float! Something else"
Basically the title, is there any way to check if a string wiuld be able to be converted to a float without causing an error? Have a python program that involves inserting a lot of numbers in sucession and I would like to not have to start again every time I accidentally make a typo
Hi!
Im wondering how to check if a value is a float or int using an if else statement.
E.g
test = int(input("Add a random number!"))
value = test / 4
if ..............?
print("Hello")
else:
print("Hello2")
I have no idea if this is even close to being the right way to do it since i just started to learn Python and have no prior experience in programming.
Can someone please show me the way to do it since I can't find the answer on the internet!!
while True:
while True:
print("Enter a number")
num1 = input("")
if (num1.isfloat()):
break
else:
continue
while True:
print("Enter a second number")
num2 = input("")
if (num2.isfloat()):
break
else:
continue
For context. I'm writing a super simple, two number calculator. And i wanted to write a section where it tests for a float. So when you type in a number, for number 1 (the variable is called num1), python is suppose to check if it is a float or not. And if it it, it will continue the script if it is. And ask for the number again if its not. However, I'm struggling to find the right syntax to check for a float. isdigit and numeric work, but for some reason isfloat() does not work for me. What am I typing wrong, I'm quite new to programming.
Hi guys, I am an absolute beginner here working on a project for a college course.
I'm trying to write a program wherein a user enters a whole number between one and fifty, and the program simply tells the user whether their number is an even or an odd. Super basic stuff.
Now, I know that all user input is automatically considered a string, and I know how to convert the input to an integer within my code, but what I want is to check to see if what they entered was an integer (as opposed to a float) to begin with. If the user enters a number that includes decimals--let's say 12.3 as an example--I want to kick back an error message to them that tells them to use a whole number.
Here's my code as it stands right now:
num = input("Please enter a whole number between 1 and 50.")
if int(num) % 2 == 0 and int(num) >= 0 and int(num) <= 50:
print("Your number is an even number")
elif int(num) % 2 == 1 and int(num) >= 0 and int(num) <= 50:
print("Your number is an odd number")
else:
print("Try again. Number must be between 1 and 50.")As you can see, I've gone ahead and converted the input to integers in my code, so as it is right now, if the user enters a float, the program won't run and gives a value error. So how do I go about making sure the number entered is not a float? I tried:
if num != float
But that's a syntax error and doesn't make any sense.
I'm sure it's something super obvious that I've just overlooked, but I am quite stumped. Thanks ahead of time for your help!
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?
I'm writing a program which relies on a user inputting an integer, is there way to check if the variable is an integer or only allow integers as input? Thanks in advance for any help.