Appending python Path object with a variable without a forward slash? - python-3.x

My code is as follows:
>>> file = 'somefile.xyz'
>>> p = Path('/Some/folder/prefix_')
If I use the / operator for Path, I get:
>>> print(p / file)
I get:
/Some/folder/prefix_/somefile.xyz
But I need:
/Some/folder/prefix_somefile.xyz
How can I do this with pathlib?

Seems to me the only way to solve this is to cast to a string and back to a Path object:
Path(str(p) + file)
Or if you don't wish to import Path locally:
p.with_stem(p.stem + file)

Related

Python redirect the path by detection of ../ from anothers path

I have a path in variable A
A=r'\\omega3t.cr.in.com\shop\recipe\fad\prod\CPL\Wite\Proton\Coach_Color_Dress.xml
I have anothers path B
B="..\..\Type\Car\Proton.xml"
By using python I would like to print entire path for path B which redrive from Path A
Expected output for C is:
C=r'\\omega3t.cr.in.com\shop\recipe\fad\prod\CPL\Type\Car\Proton.xml'
Anyone have ideas?
You could use the powerful pathlib module:
from pathlib import Path
a = A.replace('\\', '/')
b = B.replace('\\', '/')
c = Path(a) / Path(b)
print(c.resolve())
gives /omega3t.cr.in.com/shop/recipe/fad/prod/CPL/Wite/Type/Car/Proton.xml
You should check if that's really what you want. It's strange to use .. on a file path, usually that is used on a directory path.
If you really need backslashes you can still replace them:
str(c.resolve()).replace('/', '\\')
gives \omega3t.cr.in.com\shop\recipe\fad\prod\CPL\Wite\Type\Car\Proton.xml

How do you combine more than one pathlib object?

I've got two Path objects using Python's pathlib library, pathA = Path('/source/parent') and pathB = Path('/child/grandchild'). What's the most direct way to combine the two so that you get a Path('/source/parent/child/grandchild') object?
According to the docs:
You can do this easy by pathlib.PurePath(*pathsegments)
"Each element of pathsegments can be either a string representing a
path segment, an object implementing the os.PathLike interface which
returns a string, or another path object."
>>> PurePath('foo', 'some/path', 'bar')
PurePosixPath('foo/some/path/bar')
>>> PurePath(Path('foo'), Path('bar'))
PurePosixPath('foo/bar')
So for you it would be:
pathA = pathlib.Path('source/parent')
pathB = pathlib.Path('child/grandchild')
pathAB = pathlib.PurePath(pathA, pathB)
Output: source/parent/child/grandchild
Note
"When several absolute paths are given, the last is taken as an anchor
(mimicking os.path.join()’s behaviour):"
>>> PurePath('/etc', '/usr', 'lib64')
PurePosixPath('/usr/lib64')
>>> PureWindowsPath('c:/Windows', 'd:bar')
PureWindowsPath('d:bar')
Even when you do this:
pathA = pathlib.Path('/source/parent')
pathB = pathlib.Path('/child/grandchild')
pathAB = pathlib.PurePath(pathA, pathB)
Pathlib will handle pathB like a path object that is represented by a string.
Output: source/child/grandchild
pathA = Path('/source/parent')
pathB = Path('child/grandchild') * remove the first front slash
print(pathA / pathB)

Change file extension from .tar.gz to .tgz in Python3

Using pathlib, is there a simple solution to change a file extension with two suffixes like ".tar.gz" to a simple suffix like ".tgz".
Currently I tried:
import pathlib
src = pathlib.Path("path/to/archive.tar.gz")
dst = src.with_suffix("").with_suffix(".tgz")
print(dst)
I get:
path/to/archive.tgz
This question is related but not identical to Changing file extension in Python
is using path lib a requirement?
if not, the os module would work just fine:
import os
path_location = "/path/to/folder"
filename = "filename.extension"
newname = '.'.join([filename.split('.')[0], 'tgz'])
os.rename(os.path.join(path_location, filename), os.path.join(path_location, newname))
EDIT:
found this on the pathlib docs:
PurePath.with_suffix(suffix)¶
Return a new path with the suffix changed. If the original path doesn’t have a suffix, the new suffix is appended instead. If the suffix is an empty string, the original suffix is removed:
>>>
>>> p = PureWindowsPath('c:/Downloads/pathlib.tar.gz')
>>> p.with_suffix('.bz2')
PureWindowsPath('c:/Downloads/pathlib.tar.bz2')
>>> p = PureWindowsPath('README')
>>> p.with_suffix('.txt')
PureWindowsPath('README.txt')
>>> p = PureWindowsPath('README.txt')
>>> p.with_suffix('')
PureWindowsPath('README')
EDIT 2:
from pathlib import Path
p = Path('path/to/tar.gz')
new_ext = "tgz"
filename = p.stem
p.rename(Path(p.parent, "{0}.{1}".format(filename, new_ext)))
You could rename it.
import os
old_file = os.path.join("directory_where_file", "a.tar.gz")
new_file = os.path.join("directory_where_file", "b.tgz")
os.rename(old_file, new_file)
from pathlib import Path
p = Path('path/to/tar.gz')
name_without_ext = p.stem
p.rename(Path(p.parent, name_without_ext + '.' + new_ext))

Double backslashes for filepath_or_buffer with pd.read_csv

Python 3.6, OS Windows 7
I am trying to read a .txt using pd.read_csv() using relative filepath. So, from pd.read_csv() API checked out that the filepath argument can be any valid string path.
So, in order to define the relative path I use pathlib module. I have defined the relative path as:
df_rel_path = pathlib.Path.cwd() / ("folder1") / ("folder2") / ("file.txt")
a = str(df_rel_path)
Finally, I just want to use it to feed pd.read_csv() as:
df = pd.read_csv(a, engine = "python", sep = "\s+")
However, I am just getting an error stating "No such file or directory: ..." showing double backslashes on the folder path.
I have tried to manually write the path on pd.read_csv() using a raw string, that is, using r"relative/path". However, I am still getting the same result, double backslashes. Is there something I am overlooking?
You can get what you want by using os module
df_rel_path = os.path.abspath(os.path.join(os.getcwd(), "folder1", "folder2"))
This way the os module will deal with the joining the path parts with the proper separator. You can omit os.path.abspath if you read a file that's within the same directory but I wrote it for the sake of completeness.
For more info, refer to this SO question: Find current directory and file's directory
You need a filename to call pd.read_csv. In the example 'a' is a only the path and does not point to a specific file. You could do something like this:
df_rel_path = pathlib.Path.cwd() / ("folder1") / ("folder2")
a = str(df_rel_path)
df = pd.read_csv(a+'/' +'filename.txt')
With the filename your code works for me (on Windows 10):
df_rel_path = pathlib.Path.cwd() / ("folder1") / ("folder2")/ ("file.txt")
a = str(df_rel_path)
df = pd.read_csv(a)

Python 3.6 pathlib Path change name parent directory

The new Path package from the pathlib library, which has been added from Python 3.4, seems a powerful replacement of approaches such as os.path.join(), but I've some trouble working with it.
I have a path that can be anything from
folder_foo/file.csv
to
long/path/to/folder_foo/file.csv
I read the .csv file in folder_foo with pandas, modify it and want to save it to
folder_bar/file.csv
or
long/path/to/folder_bar/file.csv
Essentially I want to rename folder_foo to folder_bar in the Path object.
EDIT: example path code
csv_path = Path("long/path/to/folder_foo/file.csv")
Attempts
1
csv_path.parents[0] = csv_path.parents[0] + "_clean")
Which leads to the error TypeError: unsupported operand type(s) for +: 'PosixPath' and 'str', which means you cannot use + to combine a PosixPath with a str as described in TypeError: unsupported operand type(s) for +: 'PosixPath' and 'str'.
2
To solve this I tried the following:
csv_path.parents[0] = Path(str(csv_path.parents[0]) + "_clean")
Which however results in the error : TypeError: '_PathParents' object does not support item assignment.
Since PosixPath is not a list, this error is understandable.
3
Maybe .parts is a better approach, but
csv_path.parts[-2] = csv_path.parts[-2][:-3] + "bar"
results in: TypeError: 'tuple' object does not support item assignment.
Question
How can I easily rename the file's parent folder?
Would rather split this up for readability:
bar_folder = csv_path.parent.parent / 'folder_bar'
csv_path2 = bar_folder / csv_path.name
Having the destination folder as a variable also enables you to create the folder using for example:
bar_folder.mkdir(exist_ok=True)
You could also write a little function to replace the part of the path you want to change. Here's a runnable example:
from pathlib import Path
path1 = Path("a/b/c.txt")
path2 = Path("b/c.txt")
def rename_dir(path, src, dst):
# convert to list so that we can change elements
parts = list(path.parts)
# replace part that matches src with dst
parts[parts.index(src)] = dst
return Path(*parts)
rename_dir(path1, 'b', 'q')
#> PosixPath('a/q/c.txt')
rename_dir(path2, 'b', 'q')
#> PosixPath('q/c.txt')
Created at 2021-03-06 10:44:00 PST by reprexlite v0.4.2
EDIT: Found a cleaner solution without str()
csv_path2 = csv_path.parents[1] / (csv_path.parts[-2][:-3] + "bar") / csv_path.parts[-1]
# result
PosixPath('long/path/to/folder_bar/file.csv')
Path.parents gets the whole path to the folder minus the file. Path.parents[1] goes 2 levels up (long/path/to/), which is still a Path object. Then we get the last folder name with csv_path.parts[-2], which is a string. We apply [:-3] to get all string characters except "foo". This means we have "folder_". Then with + "bar" we get "folder_bar", which is added to our Path object. Finally we re-add the file name to our Path object with / csv_path.parts[-1].
Hack like solution
csv_path = Path(str(csv_path.parents[0])[:-3] + 'bar/' + csv_path.parts[-1])
It seems to me a bit unintuitive, however. There should be a more clean solution?

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