CODEWITHSUNDEEP
pythonpython-3.x
Tahsan
Tahsan

Reputation: 13

Conditional isn't working while checking input type int

Well I'm very very new to python programming and still learning.So I tried to create a function where I used len to count the number of letters in a string.But since, len doesn't work for integers I set up conditionals so that it would return a message saying "integers don't have length". But I'm not getting the message even when I type an integer. please help me to solve this. here is my code:

def Length_String(L):
    if type(L) == int:
        return "sorry,integers don't have length"
    else:
        return len(L)
x = input()
y = Length_String(x)
print(y)

It's not that important but still I want to know what is causing the conditional not to work. please help me.

Upvotes: 1

Views: 58

Answers (3)

kabanus
kabanus

Reputation: 25895

Note you can always type help(whatever) in a Python prompt to read some useful stuff about it:

input(...)

input([prompt]) -> string

Read a string from standard input.  The trailing newline is stripped.
If the user hits EOF (Unix: Ctl-D, Windows: Ctl-Z+Return), raise EOFError.
On Unix, GNU readline is used if enabled.  The prompt string, if given,
is printed without a trailing newline before reading.

So you always get a string. One way to see if this string could be converted to an integer is:

try:
     int(L)
     return "Error, this is an integer!"
except ValueError:
    return len(L)

Of course, this won't work for floats, so there maybe more checks you want to do (or just use float(L)). Another way

if L.isnumeric(): # or isdigit or isdecimal
    return "Error, this is a number!"
return L

Here it's worth mention that in addition to the help which can show methods you can always type dir(something) in a Python prompt so see some useful methods in a list.

Upvotes: 2

sahinakkaya
sahinakkaya

Reputation: 6056

In Python input() returns string no matter what you enter. So you don't need to check if the entered value is an int. If you still want to check it, you could do it with isinstance function:

if isinstance(L, int):
    return "sorry,integers don't have length"

Upvotes: 1

Bill the Lizard
Bill the Lizard

Reputation: 405715

They input function in Python returns a value of type str even if what you type in is an integer value.

Upvotes: 2

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