Can I use assert() to test if a String equals a recently created file in python

Question

I have a .py file with text in it:

To be, or not to be: that is the question:
Whether 'tis nobler in the mind to suffer
The slings and arrows of outrageous fortune,
Or to take arms against a sea of troubles,
And by opposing end them? To die: to sleep;

Next, I wrote this python script, which basically takes the above file (testFrom.py), adds the line number followed by a "> ", and finally adds triple quotes to then create a new file (testTo.py) and writes the new text to it. Here is the script:

inFileName = input("Enter the name of the first file: ")
outFileName = input("Enter the name of the second file: ")
lineCount = 0
newLines = ""

with open(inFileName, 'r') as readFile:
    readData = readFile.readlines() # create a list of each line
    for line in readData: # iterate through each line
        lineCount += 1
        if line == readData[0]:
            newLines += "~" + str(lineCount) + "> " + str(line)
        elif line == readData[len(readData) - 1]:
            newLines += str(lineCount) + "> " + str(line) + "~"
        else:
            newLines += str(lineCount) + "> " + str(line)
    with open(outFileName, 'w') as newFile:
        newFile.write(newLines.replace("~", "\"\"\""))  # write this to new file

print(type(newLines))

readFile.close()
newFile.close()

The script creates the following file:

"""1> To be, or not to be: that is the question:
2> Whether 'tis nobler in the mind to suffer
3> The slings and arrows of outrageous fortune,
4> Or to take arms against a sea of troubles,
5> And by opposing end them? To die: to sleep;"""

I use a seperate python script to test if the original script did its job:

org_contents = """1> To be, or not to be: that is the question:
2> Whether 'tis nobler in the mind to suffer
3> The slings and arrows of outrageous fortune,
4> Or to take arms against a sea of troubles,
5> And by opposing end them? To die: to sleep;"""
with open('testTo.py', 'r') as f:
    contents = f.read()
    print(contents)
    assert(org_contents == contents)

f.close()

And the above script gives this result:

/usr/local/bin/python3 /Users/Parent/Documents/modify/CodeChecker.py
"""1> To be, or not to be: that is the question:
2> Whether 'tis nobler in the mind to suffer
3> The slings and arrows of outrageous fortune,
4> Or to take arms against a sea of troubles,
5> And by opposing end them? To die: to sleep;"""
Traceback (most recent call last):
  File "/Users/Parent/Documents/modify/CodeChecker.py", line 9, in 
    assert(org_contents == contents)
AssertionError

I have to use the assert statement to test it because it is a school project that requires that. I understand that assert(org_contents == contents) is a logic tester. The code will move to the next line if the statement is True but will give the assertion error otherwise. Does anyone have any idea why it is giving an assertion error? -and thanks in advance for reading my long post lol

Brent Pappas · Answer

The assertion assert(org_contents == contents) returns False because it is indeed false.

Python interprets the string in org_contents as a multi-line string, and removes the leading and trailing double quotes.

If you want your assertion to pass, I would try changing org_contents to be:

org_contents = """\"\"\"1> To be, or not to be: that is the question:
2> Whether 'tis nobler in the mind to suffer
3> The slings and arrows of outrageous fortune,
4> Or to take arms against a sea of troubles,
5> And by opposing end them? To die: to sleep;\"\"\""""

Either that, or don't print triple quotes to your output file.

Can I use assert() to test if a String equals a recently created file in python

1 Answers