I am using Prompt_Toolkit to create a terminal like program. One of the commands I have is help. Basically you enter help and it will return a multiline comment. But when it is being printed, the formatting is being interpreted weird.
As you can see, when I type prompt I will return the __doc__ string which is just a formatted string with tabs.
I am not sure what the ^I are doing in there and what I should be looking up to get rid of them?
Looks like the terminal's encoding differs from yours, so it outputs certain characters as ^I as a means to represent tabs. Nothing to be worried about.
Related
i have tried to assign some string in string but some invisible character will be added automatically,
Try to run this code and you see its some invisible characters has been added \xe2\x80\x8b.
>>> "LIN+{}+5+{}:EN'".format(str(5), 2526526545852 or '')
"LIN+5+5+\xe2\x80\x8b2526526545852:EN'"
So it shoud be simple like,
>>>>"LIN+5+5+2526526545852:EN'"
Please share suggestions.
in my class we are studying python 2.7. I am using vscode to test the exercises.
exercise 1: read user input and print the length. If the user write
exit the program finish.
My code is follow:
myexit=False
while (myexit!=True):
#read user input
txt=raw_input("write a string or write exit to go out: ")
#print the user input string
print txt
if (str(txt)=='exit'):
myexit=True#exit from while
else:
print len(txt) #print the string length
print "finish"
when i test the code i get always the length of the string +1
example: if i write foo the output is 4 and no 3. When i write exit i
don't go out from the while and the output is 5.
Where i wrong ?
I have missed a module?
Thanks for your help
I am not sure exactly why this is happening, and I don't have access to a windows machine to test/verify but based on the comments above, it appears that on the version of python you are using that raw_input is only stripping the newline(\n) and not the carriage return(\r). Windows uses \r\n while unix uses \n. When raw input returns the \r is still on the string, hence the extra char. A useful debugging technique at the cli is to use the function repr() on the value to see exactly how it is represented. This is helpful to locate any stray control or invisible chars in strings.
The function rstrip() will remove all whitespace from the right side of the string, which in this case should safely remove the stray \r. It should also be safe if this code is running on a *nix like system as rstrip() will only remove the whitespace if it is present. You can also specify a set of char to strip, so if you would would like to be pedantic, you could use rstrip("\r").
txt=raw_input("write a string or write exit to go out: ").rstrip("\r")
Should fix the issue while still maintaining compatibility on different versions.
In writing a simple python application, I'm printing out some strings to the console in SublimeREPL (for python), using Python 2.7.8 and Sublime 3, 64 bit for Windows 8.1. However, I'm getting some very annoying red lines after each of the strings that I'm printing. Does someone know why this is happening?
I would appreciate any help.
Thanks!
The apostrophe ' character is causing Sublime's syntax highlighting engine to think that you're beginning a single-quoted string. Since ending a line with a string "open" is an error, it is being highlighted with the reddish invalid.illegal scope in your color scheme. It's nothing to worry about, it's just something you'll see happen with SublimeREPL when you have non-closing quotes on a line.
To verify this is the case, try opening a new file in Sublime, setting the syntax to Python, and pasting in the following code:
"This is a valid string"
"This is also valid even though it has a single quote ' char"
"This string is not valid
"""This string is valid, and doesn't have the red line
even though it has a newline, as it's triple-quoted"""
The middle (invalid Python syntax) line will have the red stripe from the end of the word valid to the right side of the window. The others won't.
I'm trying to open a program while I'm in a python script using the subprocess.call() function, It opens the program but for some reason the program doesn't allows that and just throw an "Unhandaled exception" error, I know the problem is probably in the program so there may be any other command that will open a program, fill some fields and press "Submit?"
Thanks!
Edit: I've no code to post..
str = 'd:\Softwares\X.exe'
subprocess.call(str)
I've also tried with:
subprocess.call(str,shell=True)
Try calling another program the same way. If the problem persists, the problem is with your code. If it goes away, the problem is with the program.
I think changing to 'D:/Softwares/X.exe' or one of the other string formats will help because the '\' character is the escape character ... used for example to denote a new line '\n'.
It probably works if you use forward-slashes (backslashes are escape symbols in Python). If it doesn't, write the first line like this:
str = r'd:\Softwares\X.exe'
The r tells Python that you are creating a raw string, so it will ignore escape symbols. More information at: https://docs.python.org/2/reference/lexical_analysis.html#string-literals
I am extracting text using python from a textfile created from pdf using pdftotext. It is one of 2000 files and in this particular one, a line of keywords ends in EU. The remainder of the line is blank to the naked eye and so is the following line.
The program normally strips off any trailing blanks at the end of a line and ignores the subsequent blank line.
In this instance, it is saving the whitespace which is seen when it is printed out in at textfile between "EU. " and similarly in html (Simile Exhibit).
I also printed to the command line and here I see a string of aacute. [?]
I thought the obvious way to deal with this was to search and replace the accute. I've tried to do that with a compile statement and I've played with permutations of decoding the incoming text.
Oddly though, when I print "\255" I don't get an aacute, I get an o grave.
It seems likely with this odd combination of errors that I have misunderstood something fundamental. Any tips of how to begin unravelling this?
Many thanks.
The first tip is not to print wildly to all possible output mechanisms using various unstated encodings. Find out exactly what you have got. Do this:
print repr(the_line_with_the_problem) # Python 2.x
print(ascii(the_line_with_the_problem)) # Python 3.x
and edit your question and copy/paste the result.
Second tip: When asking for help, give information about your environment:
What version of Python? What version of what operating system?
Also show locale-related info; following example is from my computer running Python 2.7 in a Windows 7 Command Prompt window::
>>> import sys, locale
>>> sys.getdefaultencoding()
'ascii'
>>> sys.stdout.encoding
'cp850'
>>> locale.getdefaultlocale()
('en_AU', 'cp1252')
>>>
Third tip: Don't use your own jargon ... the concepts "Simile Exhibit", "printed to the command line", and "compile statement" need explanation.
What is the relevance of "\255"? Where did you get that from?
Wild guesses while waiting for some facts to emerge:
(1) The offending character is U+00A0 NO-BREAK SPACE aka NBSP which appears in your text as "\xA0" and when sent to stdout in a Western European locale on Windows using a Command Prompt window would be treated as being encoded in cp850 and thus appear as a-acute. How this could be transmogrified into o-grave is a mystery.
(2) "\255" == \xAD implies the offending character is U+00AD SOFT HYPHEN but why this would be seen as o-grave is a mystery, and it's not "whitespace"; it shouldn't be shown at all, and it it is shown it should be as a hyphen/minus-sign, not a space.