Why does IsNumeric() return False when given a number from a text line-CodePudding

I am working on some python code that will evaluate each line of a file, and if that line is a number, it should return false and ignore that line. This code comes from https://github.com/geoff604/sbv2txt/blob/master/README.md and I am working to modify it.

However, no matter which line gets passed to the IsNumeric() function, it still evaluates as False. I hardcoded the same number as a string "2" and it evaluated this correctly as True.

Is there something I am missing when evaluating lines of text?

import sys

def isCaptionText(lineIndex):
    if lineIndex.isnumeric():
        print('True')
        return False
    else:
        return lineIndex

if len(sys.argv) < 3:
    print('Arguments: [source sbv filename] [destination txt filename]')
    sys.exit()

with open(sys.argv[1]) as f1:
    with open(sys.argv[2], 'a') as f2:
        lines = f1.readlines()
        for index, line in enumerate(lines):
            if isCaptionText(line):
                f2.write(line)

print('Output complete. File written as '   sys.argv[2])

The file I am analyzing is text I will list in shortened form below.

2
00:00:04,360 --> 00:00:08,861
St. Louis' home for arts,
education and culture.

3
00:00:08,861 --> 00:00:11,444
(upbeat music)

4
00:00:12,290 --> 00:00:13,610
- [Woman] But we're in a global pandemic.

5
00:00:13,610 --> 00:00:16,000
We're also in a global blood shortage.

6
00:00:16,000 --> 00:00:18,230
- [Man] The more I dug,
the more it took me back

CodePudding user response：

So, whenever you have a new line, python sees the text along with a new line. For example: if the line is 1, the f1.readlines() sees that as 1\n, hence the isNumeric will return false. The trick here is to use strip

for index, line in enumerate(Lines):
if isCaptionText(line.strip()):
   print(line)

CodePudding user response：

Because everyline in file have a newline symbol which depends on the OS you use, such as the first line 2, it is actually 2\n in Windows.
You can use replace or strip to get ride of newline symbol if you want to run your code on specific OS.

example fixed code on Windows:

with open("input.txt") as f1:
    lines = f1.readlines()
    for index, line in enumerate(lines):
        print(line.replace("\n","").isnumeric())

input.txt

2
00:00:04,360 --> 00:00:08,861
St. Louis' home for arts,
education and culture.

3
00:00:08,861 --> 00:00:11,444
(upbeat music)

4
00:00:12,290 --> 00:00:13,610
- [Woman] But we're in a global pandemic.

5
00:00:13,610 --> 00:00:16,000
We're also in a global blood shortage.

6
00:00:16,000 --> 00:00:18,230
- [Man] The more I dug,
the more it took me back

result:

True
False
False
False
False
True
False
False
False
True
False
False
False
True
False
False
False
True
False
False
False

CodePudding user response：

using try and except block

try:
    int(lineIndex)
    print('True')
    return True
except ValueError:
    return False

or using type()

if type(lineIndex) == int:
    print('True')
    return False
else:
    return lineIndex

if you have decimals check for float