Open a .log extension file in Python - python

I'm trying to open a .log extension file in Python but I keep encountering an IOError. I'm wondering if this has to do with the extension because clearly, the only way to get into that loop was if 'some.log' existed in the directory.
location = '/Users/username/Downloads'
for filename in os.listdir(location):
if filename == 'some.log':
f = open('some.log', "r")
print (f.read())
Traceback:
f = open('some.log', "r")
IOError: [Errno 2] No such file or directory: 'some.log'

When attempting to open a file in a different directory, you need to supply the absolute file path. Otherwise it attempts to open a file in the current directory.
You can use os.path.join to concatenate the location and filename
import os
location = '/Users/username/Downloads'
for filename in os.listdir(location):
if filename == 'some.log':
f = open(os.path.join(location, 'some.log'), "r")
print (f.read())

Related

How to load an image from a directory to turn it into a matrix in a for loop without getting FileNotFoundError? [duplicate]

I was trying to iterate over the files in a directory like this:
import os
path = r'E:/somedir'
for filename in os.listdir(path):
f = open(filename, 'r')
... # process the file
But Python was throwing FileNotFoundError even though the file exists:
Traceback (most recent call last):
File "E:/ADMTM/TestT.py", line 6, in <module>
f = open(filename, 'r')
FileNotFoundError: [Errno 2] No such file or directory: 'foo.txt'
So what is wrong here?
It is because os.listdir does not return the full path to the file, only the filename part; that is 'foo.txt', when open would want 'E:/somedir/foo.txt' because the file does not exist in the current directory.
Use os.path.join to prepend the directory to your filename:
path = r'E:/somedir'
for filename in os.listdir(path):
with open(os.path.join(path, filename)) as f:
... # process the file
(Also, you are not closing the file; the with block will take care of it automatically).
os.listdir(directory) returns a list of file names in directory. So unless directory is your current working directory, you need to join those file names with the actual directory to get a proper absolute path:
for filename in os.listdir(path):
filepath = os.path.join(path, filename)
f = open(filepath,'r')
raw = f.read()
# ...
Here's an alternative solution using pathlib.Path.iterdir, which yields the full paths instead, removing the need to join paths:
from pathlib import Path
path = Path(r'E:/somedir')
for filename in path.iterdir():
with filename.open() as f:
... # process the file

Looping over a folder in Python [duplicate]

I was trying to iterate over the files in a directory like this:
import os
path = r'E:/somedir'
for filename in os.listdir(path):
f = open(filename, 'r')
... # process the file
But Python was throwing FileNotFoundError even though the file exists:
Traceback (most recent call last):
File "E:/ADMTM/TestT.py", line 6, in <module>
f = open(filename, 'r')
FileNotFoundError: [Errno 2] No such file or directory: 'foo.txt'
So what is wrong here?
It is because os.listdir does not return the full path to the file, only the filename part; that is 'foo.txt', when open would want 'E:/somedir/foo.txt' because the file does not exist in the current directory.
Use os.path.join to prepend the directory to your filename:
path = r'E:/somedir'
for filename in os.listdir(path):
with open(os.path.join(path, filename)) as f:
... # process the file
(Also, you are not closing the file; the with block will take care of it automatically).
os.listdir(directory) returns a list of file names in directory. So unless directory is your current working directory, you need to join those file names with the actual directory to get a proper absolute path:
for filename in os.listdir(path):
filepath = os.path.join(path, filename)
f = open(filepath,'r')
raw = f.read()
# ...
Here's an alternative solution using pathlib.Path.iterdir, which yields the full paths instead, removing the need to join paths:
from pathlib import Path
path = Path(r'E:/somedir')
for filename in path.iterdir():
with filename.open() as f:
... # process the file

how to delete files starting with a date from python [duplicate]

I was trying to iterate over the files in a directory like this:
import os
path = r'E:/somedir'
for filename in os.listdir(path):
f = open(filename, 'r')
... # process the file
But Python was throwing FileNotFoundError even though the file exists:
Traceback (most recent call last):
File "E:/ADMTM/TestT.py", line 6, in <module>
f = open(filename, 'r')
FileNotFoundError: [Errno 2] No such file or directory: 'foo.txt'
So what is wrong here?
It is because os.listdir does not return the full path to the file, only the filename part; that is 'foo.txt', when open would want 'E:/somedir/foo.txt' because the file does not exist in the current directory.
Use os.path.join to prepend the directory to your filename:
path = r'E:/somedir'
for filename in os.listdir(path):
with open(os.path.join(path, filename)) as f:
... # process the file
(Also, you are not closing the file; the with block will take care of it automatically).
os.listdir(directory) returns a list of file names in directory. So unless directory is your current working directory, you need to join those file names with the actual directory to get a proper absolute path:
for filename in os.listdir(path):
filepath = os.path.join(path, filename)
f = open(filepath,'r')
raw = f.read()
# ...
Here's an alternative solution using pathlib.Path.iterdir, which yields the full paths instead, removing the need to join paths:
from pathlib import Path
path = Path(r'E:/somedir')
for filename in path.iterdir():
with filename.open() as f:
... # process the file

reading all the files in a directory with specific extension using glob python

I have a directory with further sub directories each having files with a specific extension. I am able to get the names of all the files using glob function:
for name in glob.glob('*/*[a-b]*'):
print(os.path.basename(name))
that prints the name of files I have in all the sub directories:
PF44_aa
PF52_aa
PF95_aa
PF38_aa
PF45_aa
PF63_aa
PF68_aa
PF39_aa
However, if I pass these file names as arguments to open the files and read the contents:
for name in glob.glob('*/*[a-b]*'):
filename=os.path.basename(name)
with open('%s' %filename) as fn:
content = fn.readlines()
I get the following error:
File "<ipython-input-194-147f38fc2684>", line 1, in <module>
with open('%s' %filename) as fn:
FileNotFoundError: [Errno 2] No such file or directory: 'PF44_aa'
I also tried giving the filename directly as input instead of %s:
for name in glob.glob('*/*[a-b]*'):
filename=os.path.basename(name)
with open(filename) as fn:
content = fn.readlines()
But still got the same error:
File "<ipython-input-193-fb125b5aa813>", line 1, in <module>
with open(filename) as fn:
FileNotFoundError: [Errno 2] No such file or directory: 'PF44_aa'
What am I doing wrong and how can I fix this?
You have to use complete path of the file to open it, you can't use just filename unless if its on the same directory as your python file. So you have to do little change in your script to make it work.
for name in glob.glob('*/*[a-b]*'):
with open(name) as fn:
content = fn.readlines()
filename is replaced by name.
here, "name" is complete path to your file.
Alternative method...
Start by first importing:
import shutil
import os
Then assign the directory to a list:
file_list = []
file_list = os.listdir('C:/filepath')
Now distinguish between files:
files = []
files = [x for x in file_list if "_aa" in x]
Now you can open and read the files in the files list using your method.
however do:
filepath + filename
with open(filepath + filename) as fn:
content = fn.readlines()
Currently you're just trying to open the file with its name, you need to include the full file path...
outcome:
"C:/filepath/PF44_aa"

Python raising FileNotFoundError for file name returned by os.listdir

I was trying to iterate over the files in a directory like this:
import os
path = r'E:/somedir'
for filename in os.listdir(path):
f = open(filename, 'r')
... # process the file
But Python was throwing FileNotFoundError even though the file exists:
Traceback (most recent call last):
File "E:/ADMTM/TestT.py", line 6, in <module>
f = open(filename, 'r')
FileNotFoundError: [Errno 2] No such file or directory: 'foo.txt'
So what is wrong here?
It is because os.listdir does not return the full path to the file, only the filename part; that is 'foo.txt', when open would want 'E:/somedir/foo.txt' because the file does not exist in the current directory.
Use os.path.join to prepend the directory to your filename:
path = r'E:/somedir'
for filename in os.listdir(path):
with open(os.path.join(path, filename)) as f:
... # process the file
(Also, you are not closing the file; the with block will take care of it automatically).
os.listdir(directory) returns a list of file names in directory. So unless directory is your current working directory, you need to join those file names with the actual directory to get a proper absolute path:
for filename in os.listdir(path):
filepath = os.path.join(path, filename)
f = open(filepath,'r')
raw = f.read()
# ...
Here's an alternative solution using pathlib.Path.iterdir, which yields the full paths instead, removing the need to join paths:
from pathlib import Path
path = Path(r'E:/somedir')
for filename in path.iterdir():
with filename.open() as f:
... # process the file

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