Question

What are the standard Python modules for handling standard output?

How do you program reread data from standard input?

What happens when an exception is raised and the program does not handle it with a try/except statement?

What type of exception does a program raise when it tries to open a nonexistent file?

What type of exception does a program raise when it uses the float number to convert a non-numeric string to a number?

What important statement do you need to write in a program that uses the math module?

Answer 1

1.)

• The output is usually written to standard output using print() method
• There is yet another standard write() that an output to files, this method can be made to write to standard output using the reference to standard output file sys.stdout

2.)

• The program can be made to read from standard input using input()
• Alternatively, we can sys.stdin reference to refer to standard input.

Example:

for x in sys.stdline:

print(x)

• the above example will read the inputs in standard input and print the data line by line

3.)

• When an exception is thrown and the program does not handle it, the expception is shown in the interpreter and the program terminates

4.)

• When we try to open a non existent file, the python interpreter throws a FileNotFoundError, with a message saying no such file or directory

5.)

• If we try to convert a non-numberic to float, python interpreter throws a ValueError saying "could not convert string to float"

6.)

• We need to write the import statement import math to use the math module