why can't I open/ interact with files through python - python

I'm new to coding and have started to try out the OS module, it occasionally it will work on specific paths.
example:
but when I try to interact with an individual file this will happen:
print(os.stat('my_file.txt'))
>>>filenotfounderror: [errno 2] no such file or directory found.
'my_file.txt'
or when I try to interact with a path that is not in my cwd then this would happen:
print(os.listdir(C:\folder\folder\folder))
>>>SyntaxError: (unicode error) 'unicodeescape' codec can't decode bytes in
position 2-3: truncated \UXXXXXXXX escape
I don't understand why this is happening and it would be great if someone could explain why this is happening, thanks.

Python tells your that my_file.txt does not exist in the current directory in your first example.
Verify that you have a file called my_file.txt and then check the current working directory of your python process with os.getcwd().
For your second example, in python the backslash \ is a special character for escape sequences in a string. For example the linefeed \n or the tab \t.
The error in your example is most likely the result of accidentaly forming an invalid escape sequence by not escaping the backslash itself like this:
print(os.listdir('C:\\folder\\folder\\folder'))

Related

Os.chdir with non-Latin characters

While learning the os module in Python and I've come across a problem.
Let's pretend my current working directory is: C:\Users\Москва\Desktop\Coding\Project 1.
I'd like to change the cwd to Desktop but since the path contains some Russian letters (Москва) it throws a Syntax error:
print(os.getcwd()) # C:\Users\Москва\Desktop\Coding\Project 1
os.chdir('C:\Users\Москва\Desktop')
SyntaxError: (unicode error) 'unicodeescape' codec can't decode bytes...
How shall I usually treat non-standard characters in paths and change the directory in my case?
It isn't about the russian, it's about the backslash with u: \U.
When you print os.getcwd, escaped backslashes goes away:
os.getcwd()
# 'C:\\Users\\chris\\Documents\\Москва\\test'
print(os.getcwd())
C:\Users\chris\Documents\Москва\test
And now if you try to use the printed one by copy-paste, python will understand \Users part as a unicode but of course fail. You can simply reproduce by executing
"\Uaaaa"
SyntaxError: (unicode error) 'unicodeescape' codec can't decode bytes in position 0-1: truncated \UXXXXXXXX escape
You can either use raw string, or use escaped backslashes:
os.chdir(r'C:\Users\sjysk\Documents\Москва')
# ^ note `r` here
os.getcwd()
# 'C:\\Users\\chris\\Documents\\Москва'
os.chdir('C:\\Users\\sjysk\\Documents\\Москва')
os.getcwd()
# 'C:\\Users\\chris\\Documents\\Москва'

Trouble with opening docx file, seems to be Unicode issue

I am a novice to python & this is my first small project
I am having trouble inputting a file directory to open a Word document. I tried this by copying & pasting the directory from my command prompt, but this Error appears after plugging it in. How do I convert the command prompt to UTF-8 or find the directory in Unicode?
#After importing necessary modules for the project, I access the file
from docx import Document
import pandas as pd
import docx
doc = Document('C:\Users\trisy\OneDrive\Desktop\classes\SP_22_courses\CS1110\pye_files\kw_txt.docx')
#Error message
doc = Document('C:\Users\xxx\OneDrive\Desktop\classes\SP_22_courses\xxx\pye_files\kw_txt.docx')
^
SyntaxError: (unicode error) 'unicodeescape' codec can't decode bytes in position 2-3: truncated \UXXXXXXXX escape
The problem is caused by the backslashes in that pathname, combined with certain other characters.
In Python, putting \x in a string can have special behavior depending on what x is.
For example, \n does not mean "backslash n"; it means a newline character.
\U is one of these special cases.
To get around this, you have two options:
Use "raw strings". Put an r before the string. r'C:\Users\...' The r tells Python that backslashes should have no special meaning.
Use forward slashes in the file path. 'C:/Users/...' These will work even on Windows.

How to load CSV file in Jupyter Notebook?

I'm new and studying machine learning. I stumble upon a tutorial I found online and I'd like to make the program work so I'll get a better understanding. However, I'm getting problems about loading the CSV File into the Jupyter Notebook.
I get this error:
File "<ipython-input-2-70e07fb5b537>", line 2
student_data = pd.read_csv("C:\Users\xxxx\Desktop\student-intervention-
system\student-data.csv")
^
SyntaxError: (unicode error) 'unicodeescape' codec can't decode bytes in
position 2-3: truncated \UXXXXXXXX escape
and here is the code:
I followed tutorials online regarding this error but none worked. Does anyone know how to fix it?
3rd attempt with r"path"
I've tried also "\" and utf-8 but none worked.
I'm using the latest version of Anaconda
Windows 7
Python 3.7
Use raw string notation for your Windows path. In python '\' have meaning in python. Try instead do string like this r"path":
student_data = pd.read_csv(r"C:\Users\xxxx\Desktop\student-intervention-
system\student-data.csv")
If it doesnt work try this way:
import os
path = os.path.join('c:' + os.sep, 'Users', 'xxxx', 'Desktop', 'student-intervention-system', 'student-data.csv')
student_data = pd.read_csv(path)
Either replace all backslashes \ with frontslashes / or place a r before your filepath string to avoid this error. It is not a matter of your folder name being too long.
As Bohun Mielecki mentioned, the \ character which is typically used to denote file structure in Windows has a different function when written within a string.
From Python3 Documentation: The backslash \ character is used to escape characters that otherwise have a special meaning, such as newline, backslash itself, or the quote character.
How this particularly affects your statement is that in the line
student_data = pd.read_csv("C:\Users\xxxx\Desktop\student-intervention-
system\student-data.csv")
\Users matches the escape sequence \Uxxxxxxxx whereby xxxxxxxx refers to a Character with 32-bit hex value xxxxxxxx. Because of this, Python tries to find a 32-bit hex value. However as the -sers from Users doesn't match the xxxxxxxx format, you get the error:
SyntaxError: (unicode error) 'unicodeescape' codec can't decode bytes in
position 2-3: truncated \UXXXXXXXX escape
The reason why your code works now is that you have placed a r in front of 'C:\Users\xxxx\Desktop\project\student-data.csv'. This tells python not to process the backslash character / as it usually does and read the whole string as-is.
I hope this helps you better understand your problem. If you need any more clarification, do let me know.
Source: Python 3 Documentation
I had the same problem. I tried to encode it with 'Latin-1' and it worked for me.
autos = pd.read_csv('filename',encoding = "Latin-1")
Try changing \ to /: -
import pandas as pd
student_data = pd.read_csv("C:/Users/xxxx/Desktop/student-intervention-
system/student-data.csv")
print(student data)
OR
import pandas as pd
student_data = pd.read_csv("C:/Users/xxxx/Desktop/student-intervention- system/student-data.csv"r)
print(student data)
Try this student_data = pd.read_csv("C:/Users/xxxx/Desktop/student-intervention-
system/student-data.csv").
Replacing backslashes in that code it will work for you.
You probably have a file name with a backlash... try to write the path using two backlashes instead of one.
student_data = pd.read_csv("C:\\Users\\xxxx\\Desktop\\student-intervention-system\\student-data.csv")
Try
pd.read_csv('file_name',encoding = "utf-8")
I found the problem. The problem is my folder name that is really long. I changed my folder name into "project" and the data is now finally loaded! Silly!
Please open notepad, write csv format data into the file and opt 'Save As' to save the file with format .csv.
E.g. Train.csv
Use this file, ensure you mention the same path correctly for the above saved CSV file during python coding.
Import pandas as pd
df=pd.read_csv('C:/your_path/Train.csv')
I've seen people using existing .txt/other format files to covert their format to .csv by just renaming. Which actually does nothing than changing the name of the file. It doesn't become a CSV file at all.
Hope this helps. 🙏🙏
Generally this kind of error arises if there is any space in file path...
df=pd.read_csv('/home/jovyan/binder/kidney disease.csv')
above command will create an error and will get resolved when it is
df=pd.read_csv('/home/jovyan/binder/kidney_disease.csv')
replaced space with underscore
To begin with, this has nothing to do with Jupyter. This is a pure Python problem!
In Python, as in most languages, a backslash is an special (escape) character in strings, for example "foo\"bar" is the string foo"bar without causing a syntax error. Also, "foo\nbar" is the strings foo and bar with a newline in between. There are many more escapes.
In your case, the meaning of \ in your path is literal, i.e. you actually want a backslash appearing in the string.
One option is to escape the backslash itself with another backslash: "foo\\bar" amounts to the string foo\bar. However, in your case, you have several of these, so for readability you might want to switch on "raw string mode", which disables (almost all) escapes:
r"foo\bar\baz\quux\etc"
will produce
foo\bar\baz\quuz\etc
As a matter of programming style, though, if you want your code to be portable, it is better to use os.path.join which knows the right path separator for your OS/platform:
In [1]: import os.path
In [2]: os.path.join("foo", "bar", "baz")
Out[2]: 'foo/bar/baz'
on Windows, that would produce foo\bar\baz.
import pandas as pd
data=pd.read_csv("C:\Users\ss\Desktop\file or csv file name.csv")
just place the csv file on the desktop

Cannot launch exec in subprocess with path

I'm trying to launch an executable from python subprocess and I have a problem with the path.
I'm trying to run newman.cmd which is located in
C:\Users\<myself>\AppData\Roaming\npm
I try
subprocess.run("C:\Users\<myself>AppData\Roaming\npm\newman.cmd run","shell=True")
which fails, indicating:
Syntax Error: (unicode error) 'unicodeescape' codec can't decode bytes in position 2-3: truncated \UXXXXXXXX escape: C:\knxnet\test_differentiel.py, line 71, pos 23
subprocess.run("C:\Users\<myself>\AppData\Roaming\npm\newman.cmd run","shell=True")
If I copy newman.cmd and the appropriate folders in my local path, I end up launching the command as expected, ie. this works:
subprocess.run("newman.cmd -h")
I checked the path and it gives me the following:
ENV = <irrelevant info> ;C:\Users\<myself>\AppData\Roaming\npm
so I though it would find it ? how can I do to avoid copying executables in my current directory ?
thanks for any help ...
Well, I found out the answer thanks to SO ... "Unicode Error "unicodeescape" codec can't decode bytes... Cannot open text files in Python 3
It is interpreted as unicode followed by an unwanted character ... the position indicated in the error was the quote's position, so I didn't catch the hint.
so I tried with r:
subprocess.run(r"C:\Users\a.joly\AppData\Roaming\npm\newman.cmd -h")
and it works. It also works if I double the "\".
thanks for your time ...

Python - Must add r when opening a file

I have several .py files and I can open my file everywhere, except in my test.py file (I test scripts and functions there) instead of this:
file = open("C:\Users\User\Desktop\key_values.txt", "r")
I need to use this (with r) to avoid error:
file = open(r"C:\Users\User\Desktop\key_values.txt", "r")
I get this error: (when I try to open a file without r in my test.py script)
SyntaxError: (unicode error) 'unicodeescape' codec can't decode bytes in position 2-3: truncated \UXXXXXXXX escape
Any idea why is this happening ?
Backslash is an escape character, so you can include characters like "\n" (new line) and "\t" (tab). The r before the string means means "my backslashes are not escape characters".
Interestingly, it looks like your string "C:\Users\User\Desktop\key_values.txt" works ok in python 2 because none of the backslashes are part of anything looking like a known escape sequence. But in python 3, "\Uxxxx" indicates a unicode character. So maybe that is why some of your python files can cope and some can't.
The other answers are OK.. but this a time saving trick:
Try using slashes instead of backslashes:
file = open("C:/Users/User/Desktop/key_values.txt", "r")
It works in Windows. Tried with Python 2.7
Hope this helps

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