CODEWITHSUNDEEP
pythonstring
user3232726
user3232726

Reputation: 211

TypeError: 'str' object is not callable

I am trying to generate a random number convert it to and int then print the number, but i am getting the error 'str' object is not callable. I have googled the problem but I cant seem to find what i am doing wrong.

here is my code:

import random
import time

while(True):
    #generate a random frequency from 0Hz to 1MHz   
    frequency = int(random.randrange(0,1000000))    
    print('Frequency: %d'('frequency'))
    print('Frequency: ',frequency, ' Hz')

    print("sleep for 2 seconds")
    time.sleep(2)  # Delay for 1 minute (60 seconds)

The error i get is:

Traceback(most recent call last):
File "frequency1.py", line 7, in <module>
print('Frequency: %d'('Frequency'))
TypeError: 'str' object is not callable

Upvotes: 0

Views: 3967

Answers (3)

Bhargav Rao
Bhargav Rao

Reputation: 52181

Your print statement is incorrect. It should instead be

print('Frequency: %d'%(frequency))

When you do 'Frequency: %d'(frequency), You are trying to call the string 'Frequency: %d' as a function. This is why you get the error TypeError: 'str' object is not callable. The error can be decoded as 'str' object which is 'Frequency: %d' is not callable i.e. it is not a function that can be called

You can try format instead as it is better. Do read PEP - 3101 that mentions about format and the % operator. The print statement can be written as 

print('Frequency: {}'.format(frequency))

The changed program after correcting the missing % symbol can be written as 

import random
import time

while(True):
    #generate a random frequency from 0Hz to 1MHz   
    frequency = int(random.randrange(0,1000000))    
    print('Frequency: %d'%(frequency))            # Note the added % 
    print('Frequency: ',frequency, ' Hz')

    print("sleep for 2 seconds")
    time.sleep(2)  # Delay for 1 minute (60 seconds)

This program on execution would give the following output. 

Frequency: 753865
Frequency:  753865  Hz
sleep for 2 seconds
Frequency: 152017
Frequency:  152017  Hz
sleep for 2 seconds

Also note that the , in python adds a space. Hence you need not do print('Frequency: ',frequency, ' Hz') but instead can directly write print('Frequency:',frequency, 'Hz').

Upvotes: 4

unwind
unwind

Reputation: 400109

String interpolation is done using the % operator, but you're trying to call the string as if it were a function instead which explains the error.

It should be:

print("Frequency: %d" % frequency)

Note that the right-hand side of the % only needs to be a tuple if there is more than one value, single values can be passed bare like above.

Also, in Python 3 it's more common with the more modern format() syntax:

printf("Frequency: {}".format(frequency))

Upvotes: 2

Anandhakumar R
Anandhakumar R

Reputation: 391

>>> while(True):
...     frequency = int(random.randrange(0,1000000))    
...     print('Frequency: %d'%frequency)
...     print('Frequency: ',frequency, ' Hz')
...     time.sleep(2)  # Delay for 1 minute (60 seconds)

...

OUtput

Frequency: 720460 ('Frequency: ', 720460, ' Hz')

Frequency: 559979 ('Frequency: ', 559979, ' Hz')

Frequency: 649103 ('Frequency: ', 649103, ' Hz')

Upvotes: 1

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