A custom function to return the length of a string

I want to define a function which takes an input from the user, returns the length of the input string and prints this out.

I have the following code:

def str_length(my_string):

    my_string = input("give me a string: ")

    return len(my_string)

print(str_length(my_string))

This code does not work. When I exchange the parameter in the last line to "hello" the code works.

def str_length(my_string):

    my_string = input("give me a string: ")

    return len(my_string)

print(str_length("hello"))

Can anyone explain to me why the first code does not work while the second one works? I am totally confused :-(

edited Jan 2 at 10:28

Brian Tompsett - 汤莱恩

4,2421339102

asked Jan 2 at 10:13

Comtron

123

4

Why is the function taking a parameter at all? It's not using it

– UnholySheep
Jan 2 at 10:15

Thank you! I am new to coding. I thought, I need to add a parameter. But now I understand :-)

– Comtron
Jan 2 at 10:20

2

"This code does not work." is not a helpful statement. Please provide the input, the actual output and the expected output in your question. If your code is throwing an error, you should provide the complete error stack in your question.

– Mike Scotty
Jan 2 at 10:21

Welcome to StackOverflow! You may find the explanations given at idownvotedbecau.se helpful to avoid accidentally posting stuff which has downvote reasons within.

– Alfe
Jan 2 at 10:23

1

@Alfe: thanks! I assume you are referring to the same issue as Mike Scotty. As mentioned, I am new to StackOverflow and I will be more precise in the future.

– Comtron
Jan 2 at 10:37

|
show 1 more comment

I want to define a function which takes an input from the user, returns the length of the input string and prints this out.

I have the following code:

def str_length(my_string):

    my_string = input("give me a string: ")

    return len(my_string)

print(str_length(my_string))

This code does not work. When I exchange the parameter in the last line to "hello" the code works.

def str_length(my_string):

    my_string = input("give me a string: ")

    return len(my_string)

print(str_length("hello"))

Can anyone explain to me why the first code does not work while the second one works? I am totally confused :-(

edited Jan 2 at 10:28

Brian Tompsett - 汤莱恩

4,2421339102

asked Jan 2 at 10:13

Comtron

123

4

Why is the function taking a parameter at all? It's not using it

– UnholySheep
Jan 2 at 10:15

Thank you! I am new to coding. I thought, I need to add a parameter. But now I understand :-)

– Comtron
Jan 2 at 10:20

2

"This code does not work." is not a helpful statement. Please provide the input, the actual output and the expected output in your question. If your code is throwing an error, you should provide the complete error stack in your question.

– Mike Scotty
Jan 2 at 10:21

Welcome to StackOverflow! You may find the explanations given at idownvotedbecau.se helpful to avoid accidentally posting stuff which has downvote reasons within.

– Alfe
Jan 2 at 10:23

1

@Alfe: thanks! I assume you are referring to the same issue as Mike Scotty. As mentioned, I am new to StackOverflow and I will be more precise in the future.

– Comtron
Jan 2 at 10:37

|
show 1 more comment

I want to define a function which takes an input from the user, returns the length of the input string and prints this out.

I have the following code:

def str_length(my_string):

    my_string = input("give me a string: ")

    return len(my_string)

print(str_length(my_string))

This code does not work. When I exchange the parameter in the last line to "hello" the code works.

def str_length(my_string):

    my_string = input("give me a string: ")

    return len(my_string)

print(str_length("hello"))

Can anyone explain to me why the first code does not work while the second one works? I am totally confused :-(

edited Jan 2 at 10:28

Brian Tompsett - 汤莱恩

4,2421339102

asked Jan 2 at 10:13

Comtron

123

I want to define a function which takes an input from the user, returns the length of the input string and prints this out.

I have the following code:

def str_length(my_string):

    my_string = input("give me a string: ")

    return len(my_string)

print(str_length(my_string))

This code does not work. When I exchange the parameter in the last line to "hello" the code works.

def str_length(my_string):

    my_string = input("give me a string: ")

    return len(my_string)

print(str_length("hello"))

Can anyone explain to me why the first code does not work while the second one works? I am totally confused :-(

python string function

edited Jan 2 at 10:28

Brian Tompsett - 汤莱恩

4,2421339102

asked Jan 2 at 10:13

Comtron

123

edited Jan 2 at 10:28

Brian Tompsett - 汤莱恩

4,2421339102

asked Jan 2 at 10:13

Comtron

123

edited Jan 2 at 10:28

Brian Tompsett - 汤莱恩

4,2421339102

edited Jan 2 at 10:28

Brian Tompsett - 汤莱恩

4,2421339102

edited Jan 2 at 10:28

Brian Tompsett - 汤莱恩

4,2421339102

asked Jan 2 at 10:13

Comtron

123

asked Jan 2 at 10:13

Comtron

123

asked Jan 2 at 10:13

Comtron

123

4

Why is the function taking a parameter at all? It's not using it

– UnholySheep
Jan 2 at 10:15

Thank you! I am new to coding. I thought, I need to add a parameter. But now I understand :-)

– Comtron
Jan 2 at 10:20

2

"This code does not work." is not a helpful statement. Please provide the input, the actual output and the expected output in your question. If your code is throwing an error, you should provide the complete error stack in your question.

– Mike Scotty
Jan 2 at 10:21

Welcome to StackOverflow! You may find the explanations given at idownvotedbecau.se helpful to avoid accidentally posting stuff which has downvote reasons within.

– Alfe
Jan 2 at 10:23

1

@Alfe: thanks! I assume you are referring to the same issue as Mike Scotty. As mentioned, I am new to StackOverflow and I will be more precise in the future.

– Comtron
Jan 2 at 10:37

|
show 1 more comment

4

Why is the function taking a parameter at all? It's not using it

– UnholySheep
Jan 2 at 10:15

Thank you! I am new to coding. I thought, I need to add a parameter. But now I understand :-)

– Comtron
Jan 2 at 10:20

2

"This code does not work." is not a helpful statement. Please provide the input, the actual output and the expected output in your question. If your code is throwing an error, you should provide the complete error stack in your question.

– Mike Scotty
Jan 2 at 10:21

Welcome to StackOverflow! You may find the explanations given at idownvotedbecau.se helpful to avoid accidentally posting stuff which has downvote reasons within.

– Alfe
Jan 2 at 10:23

1

@Alfe: thanks! I assume you are referring to the same issue as Mike Scotty. As mentioned, I am new to StackOverflow and I will be more precise in the future.

– Comtron
Jan 2 at 10:37

Why is the function taking a parameter at all? It's not using it

– UnholySheep
Jan 2 at 10:15

Thank you! I am new to coding. I thought, I need to add a parameter. But now I understand :-)

– Comtron
Jan 2 at 10:20

"This code does not work." is not a helpful statement. Please provide the input, the actual output and the expected output in your question. If your code is throwing an error, you should provide the complete error stack in your question.

– Mike Scotty
Jan 2 at 10:21

Welcome to StackOverflow! You may find the explanations given at idownvotedbecau.se helpful to avoid accidentally posting stuff which has downvote reasons within.

– Alfe
Jan 2 at 10:23

@Alfe: thanks! I assume you are referring to the same issue as Mike Scotty. As mentioned, I am new to StackOverflow and I will be more precise in the future.

– Comtron
Jan 2 at 10:37

|
show 1 more comment

2 Answers
2

active

oldest

votes

You should define it like this:

def str_length():

    my_string = input("give me a string: ")

    return len(my_string)

print(str_length())

When you call the function with my_string you get NameError because there is no my_string define yet. you define it inside the function. (After you call it). that is the reason.

Thanks to @prashantrana, You can also define your function like this:

def str_length(my_string):

    return len(my_string)



my_string = input("give me a string: ")

print(str_length(my_string))

The difference here is that we get input from user out of the function scope, the pass it to function.

edited Jan 2 at 10:25

answered Jan 2 at 10:16

Mehrdad Pedramfar

6,33411643

Million thanks! :-)

– Comtron
Jan 2 at 10:18

your welcome @Comtron, Please consider this: stackoverflow.com/help/someone-answers

– Mehrdad Pedramfar
Jan 2 at 10:19

@mehrdad-pedramfar you can add another way where user pass the string as parameter to the function . both case

– prashant rana
Jan 2 at 10:19

I voted up :-)Thanks again!

– Comtron
Jan 2 at 10:22

@prashantrana yes, thanks, i will update.

– Mehrdad Pedramfar
Jan 2 at 10:22

|
show 4 more comments

As @UnholySheep pointed out, your function is taking a parameter it doesn't seem to need.

Let's break it down

Def str_length (): # start of function definition

    # promt user for the string and put it in the variable "my _string"

    my_string = input ("give me a string:")

    # return the length of input string 

    return len(my_string)



print(str_length ()) # the function is called inside print () and therefore returns the length of the user input string to print () to be printed on screen.

answered Jan 2 at 10:27

alfandango

4616

add a comment |

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2 Answers
2

active

oldest

votes

2 Answers
2

active

oldest

votes

You should define it like this:

def str_length():

    my_string = input("give me a string: ")

    return len(my_string)

print(str_length())

When you call the function with my_string you get NameError because there is no my_string define yet. you define it inside the function. (After you call it). that is the reason.

Thanks to @prashantrana, You can also define your function like this:

def str_length(my_string):

    return len(my_string)



my_string = input("give me a string: ")

print(str_length(my_string))

The difference here is that we get input from user out of the function scope, the pass it to function.

edited Jan 2 at 10:25

answered Jan 2 at 10:16

Mehrdad Pedramfar

6,33411643

Million thanks! :-)

– Comtron
Jan 2 at 10:18

your welcome @Comtron, Please consider this: stackoverflow.com/help/someone-answers

– Mehrdad Pedramfar
Jan 2 at 10:19

@mehrdad-pedramfar you can add another way where user pass the string as parameter to the function . both case

– prashant rana
Jan 2 at 10:19

I voted up :-)Thanks again!

– Comtron
Jan 2 at 10:22

@prashantrana yes, thanks, i will update.

– Mehrdad Pedramfar
Jan 2 at 10:22

|
show 4 more comments

You should define it like this:

def str_length():

    my_string = input("give me a string: ")

    return len(my_string)

print(str_length())

When you call the function with my_string you get NameError because there is no my_string define yet. you define it inside the function. (After you call it). that is the reason.

Thanks to @prashantrana, You can also define your function like this:

def str_length(my_string):

    return len(my_string)



my_string = input("give me a string: ")

print(str_length(my_string))

The difference here is that we get input from user out of the function scope, the pass it to function.

edited Jan 2 at 10:25

answered Jan 2 at 10:16

Mehrdad Pedramfar

6,33411643

Million thanks! :-)

– Comtron
Jan 2 at 10:18

your welcome @Comtron, Please consider this: stackoverflow.com/help/someone-answers

– Mehrdad Pedramfar
Jan 2 at 10:19

@mehrdad-pedramfar you can add another way where user pass the string as parameter to the function . both case

– prashant rana
Jan 2 at 10:19

I voted up :-)Thanks again!

– Comtron
Jan 2 at 10:22

@prashantrana yes, thanks, i will update.

– Mehrdad Pedramfar
Jan 2 at 10:22

|
show 4 more comments

You should define it like this:

def str_length():

    my_string = input("give me a string: ")

    return len(my_string)

print(str_length())

When you call the function with my_string you get NameError because there is no my_string define yet. you define it inside the function. (After you call it). that is the reason.

Thanks to @prashantrana, You can also define your function like this:

def str_length(my_string):

    return len(my_string)



my_string = input("give me a string: ")

print(str_length(my_string))

The difference here is that we get input from user out of the function scope, the pass it to function.

edited Jan 2 at 10:25

answered Jan 2 at 10:16

Mehrdad Pedramfar

6,33411643

You should define it like this:

def str_length():

    my_string = input("give me a string: ")

    return len(my_string)

print(str_length())

When you call the function with my_string you get NameError because there is no my_string define yet. you define it inside the function. (After you call it). that is the reason.

Thanks to @prashantrana, You can also define your function like this:

def str_length(my_string):

    return len(my_string)



my_string = input("give me a string: ")

print(str_length(my_string))

The difference here is that we get input from user out of the function scope, the pass it to function.

edited Jan 2 at 10:25

answered Jan 2 at 10:16

Mehrdad Pedramfar

6,33411643

edited Jan 2 at 10:25

answered Jan 2 at 10:16

Mehrdad Pedramfar

6,33411643

answered Jan 2 at 10:16

Mehrdad Pedramfar

6,33411643

answered Jan 2 at 10:16

Mehrdad Pedramfar

6,33411643

Million thanks! :-)

– Comtron
Jan 2 at 10:18

your welcome @Comtron, Please consider this: stackoverflow.com/help/someone-answers

– Mehrdad Pedramfar
Jan 2 at 10:19

@mehrdad-pedramfar you can add another way where user pass the string as parameter to the function . both case

– prashant rana
Jan 2 at 10:19

I voted up :-)Thanks again!

– Comtron
Jan 2 at 10:22

@prashantrana yes, thanks, i will update.

– Mehrdad Pedramfar
Jan 2 at 10:22

|
show 4 more comments

Million thanks! :-)

– Comtron
Jan 2 at 10:18

your welcome @Comtron, Please consider this: stackoverflow.com/help/someone-answers

– Mehrdad Pedramfar
Jan 2 at 10:19

@mehrdad-pedramfar you can add another way where user pass the string as parameter to the function . both case

– prashant rana
Jan 2 at 10:19

I voted up :-)Thanks again!

– Comtron
Jan 2 at 10:22

@prashantrana yes, thanks, i will update.

– Mehrdad Pedramfar
Jan 2 at 10:22

Million thanks! :-)

– Comtron
Jan 2 at 10:18

your welcome @Comtron, Please consider this: stackoverflow.com/help/someone-answers

– Mehrdad Pedramfar
Jan 2 at 10:19

@mehrdad-pedramfar you can add another way where user pass the string as parameter to the function . both case

– prashant rana
Jan 2 at 10:19

I voted up :-)Thanks again!

– Comtron
Jan 2 at 10:22

@prashantrana yes, thanks, i will update.

– Mehrdad Pedramfar
Jan 2 at 10:22

|
show 4 more comments

As @UnholySheep pointed out, your function is taking a parameter it doesn't seem to need.

Let's break it down

Def str_length (): # start of function definition

    # promt user for the string and put it in the variable "my _string"

    my_string = input ("give me a string:")

    # return the length of input string 

    return len(my_string)



print(str_length ()) # the function is called inside print () and therefore returns the length of the user input string to print () to be printed on screen.

answered Jan 2 at 10:27

alfandango

4616

add a comment |

As @UnholySheep pointed out, your function is taking a parameter it doesn't seem to need.

Let's break it down

Def str_length (): # start of function definition

    # promt user for the string and put it in the variable "my _string"

    my_string = input ("give me a string:")

    # return the length of input string 

    return len(my_string)



print(str_length ()) # the function is called inside print () and therefore returns the length of the user input string to print () to be printed on screen.

answered Jan 2 at 10:27

alfandango

4616

add a comment |

As @UnholySheep pointed out, your function is taking a parameter it doesn't seem to need.

Let's break it down

Def str_length (): # start of function definition

    # promt user for the string and put it in the variable "my _string"

    my_string = input ("give me a string:")

    # return the length of input string 

    return len(my_string)



print(str_length ()) # the function is called inside print () and therefore returns the length of the user input string to print () to be printed on screen.

answered Jan 2 at 10:27

alfandango

4616

As @UnholySheep pointed out, your function is taking a parameter it doesn't seem to need.

Let's break it down

Def str_length (): # start of function definition

    # promt user for the string and put it in the variable "my _string"

    my_string = input ("give me a string:")

    # return the length of input string 

    return len(my_string)



print(str_length ()) # the function is called inside print () and therefore returns the length of the user input string to print () to be printed on screen.

answered Jan 2 at 10:27

alfandango

4616

answered Jan 2 at 10:27

alfandango

4616

answered Jan 2 at 10:27

alfandango

4616

answered Jan 2 at 10:27

alfandango

4616

add a comment |

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