Print function and normal string in python

Question

I am using text that is stored from the file.txt and it used for some analyses. After reading text from that file i seeing difference in printed variable value and actual value stored in that variable

file=open("message.txt", "r")
message=file.read()
print(message)

Printed output: 'MSH|^~\\&|GHH LAB|ELAB-3|GHH OE|BLDG4|200202150930||ORU^R01|CNTRL-3456|P|2.4'

Above result contains printed value of my message. Now i am comparing printed value with the actual value in the message

if message == 'MSH|^~\\&|GHH LAB|ELAB-3|GHH OE|BLDG4|200202150930||ORU^R01|CNTRL-3456|P|2.4':
        print("match found")
else:
        print("No match found")

Output: No Match found

I tried with str() and repr() methods again it is not returning the correct result

It appears your actual message contains the quotes as part of the string…!? — deceze, Oct 29 '19 at 07:27
Print the `repr` of the message and literally copy and paste that as the string literal to test against. — deceze, Oct 29 '19 at 07:28
So, instead of guessing what string you need to form, `print(repr(message))` and copy and paste that exactly as is into `if message == `. — deceze, Oct 29 '19 at 08:02
@cricket_007 i tried file.read().rstrip() but returning same result — Dhanasekar Chellamuthu, Oct 29 '19 at 08:03
@deceze but using repr it is returning `'MSH|^~\\\\&|GHH LAB|ELAB-3|GHH OE|BLDG4|200202150930||ORU^R01|CNTRL-3456|P|2.4'` adding more back slash compred to input. — Dhanasekar Chellamuthu, Oct 29 '19 at 08:06
Well, then that's the correct representation of your message. — deceze, Oct 29 '19 at 08:07
@deceze but in my input `'MSH|^~\\&|GHH LAB|ELAB-3|GHH OE|BLDG4|200202150930||ORU^R01|CNTRL-3456|P|2.4'` but in output `'MSH|^~\\\\&|GHH LAB|ELAB-3|GHH OE|BLDG4|200202150930||ORU^R01|CNTRL-3456|P|2.4'` — Dhanasekar Chellamuthu, Oct 29 '19 at 08:12
Yes. Backslashes have a special meaning and need to be escaped. `repr` gives you *the valid representation* of the string. — deceze, Oct 29 '19 at 08:15
It's the *correct* result. Read https://stackoverflow.com/q/24085680/476. — deceze, Oct 29 '19 at 08:25

score 0 · Answer 1 · answered Oct 29 '19 at 07:50

0

You need to escape the backslash characters in the string literal in your code using \\\\. Also you should strip() the contents of the file as mentioned.

The following works for me:

file = open("message.txt", "r")
message = file.read().strip()
print(message)
if message == 'MSH|^~\\\\&|GHH LAB|ELAB-3|GHH OE|BLDG4|200202150930||ORU^R01|CNTRL-3456|P|2.4':
        print("match found")
else:
        print("No match found")

answered Oct 29 '19 at 07:50

Holy Mackerel

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Thanks for answering.can you explain in detail – Dhanasekar Chellamuthu Oct 29 '19 at 07:57
But in your printed value four backslash is there but in my input only two backslash is there – Dhanasekar Chellamuthu Oct 29 '19 at 08:08
You need four backslashes in the code so Python interprets the string correctly but only two backslashes in the file. See https://stackoverflow.com/a/19095831/1619769 – Holy Mackerel Oct 29 '19 at 08:22
Any other ways to avoid back slashing – Dhanasekar Chellamuthu Oct 29 '19 at 08:24

Print function and normal string in python

1 Answers1