File Input/Output

Question 1

How to create a file

Answer 1

• create variable to assign text file to
• open(‘TEXTFILENAME.TXT’, ‘READWRITEAPPEND’)
• this makes an empty file in the current folder
• using w overwrites anything previously written in the file

Question 2

How to check CWD

Answer 2

impost os

os. getcwd()
os. chdir(‘/-/-/-/’) # Change directory

Question 3

Write into a data file

Answer 3

.write() # used to write lines of text

- end file writing by using my_file.close()

Question 4

Read data out of the text file

Answer 4

• create empty variable
• open file
• assign a variable to file.readline()
• while the variable holding the line is not empty
• append the line.rstrip() (to remove empty characters) to empty variable and repeat the step (appending each line through iteration)
• close file

Question 5

file reading exceptions

Answer 5

use try and except for example is the file is empty, or the file does not exist

Question 6

exceptions

Answer 6

• a situation that can cause a program to start acting erratically or to crash entirely
• using try and except works to solve these issues
• EAFP (easier to ask forgiveness than permission)

Question 7

exception classes

Answer 7

there are many exception classes derived from base exceptions

Question 8

try and except

Answer 8

• more than one except block may be used if it is anticipated that more than 1 class of error may be encountered
• when used by itself, except encounters all exceptions