NPY file icon

NPY File Extension

NumPy Data Format

What is NPY file?

Binary files with the extension .NPY contain data arrays from NumPy, which is a package of the Python programming language. These files can be read independently of the platform on which they were saved. They store a single array including information about the data type and their values.

Files in the .NPY format can hold any individual arrays used in applications or scripts of Python with the NumPy package.

The format of these files allows saving complete information about the shape and dtype of the data. This enables the reconstruction - loading of the array on any other computer. Data stored in .NPY files:

  • may represent all types of arrays, including those with objects or nested records,
  • are represented in a binary, native mode,
  • allow for memory mapping,
  • facilitate reverse engineering of programs - .NPY is designed to be as simple as possible.

Reading and writing data to files is intuitive thanks to a series of available functions from the NumPy package. The version of the format is independent of the version of the NumPy package that is intended to handle it.

Way to Store Multiple NumPy Arrays

Files with the extension .NPY can also be part of a .NPZ package. This is a ZIP-compressed directory containing multiple .NPY files corresponding to individual tables. Therefore, it possesses the same properties as files in the NPY data format. The format has several versions and is continuously developed, maintaining backward compatibility.

Programs which support NPY file extension

The following listing features NPY-compatible programs. Files with NPY suffix can be copied to any mobile device or system platform, but it may not be possible to open them properly on target system.

Programs that support NPY file

Windows Windows

Updated: 04/05/2024

How to open file with NPY extension?

There can be multiple causes why you have problems with opening NPY files on given system. Fortunately, most common problems with NPY files can be solved without in-depth IT knowledge, and most importantly, in a matter of minutes. The following is a list of guidelines that will help you identify and solve file-related problems.

Step 1. Install NumPy software

Install software to open NPY file The most common reason for such problems is the lack of proper applications that supports NPY files installed on the system. The solution is straightforward, just download and install NumPy. Above you will find a complete listing of programs that support NPY files, classified according to system platforms for which they are available. The safest method of downloading NumPy installed is by going to developer’s website (Numpy developers) and downloading the software using provided links.

Step 2. Check the version of NumPy and update if needed

Update software that support file extension NPYIf you already have NumPy installed on your systems and NPY files are still not opened properly, check if you have the latest version of the software. Sometimes software developers introduce new formats in place of that already supports along with newer versions of their applications. The reason that NumPy cannot handle files with NPY may be that the software is outdated. All of the file formats that were handled just fine by the previous versions of given program should be also possible to open using NumPy.

Step 3. Assign NumPy to NPY files

If the issue has not been solved in the previous step, you should associate NPY files with latest version of NumPy you have installed on your device. The next step should pose no problems. The procedure is straightforward and largely system-independent

Associate software with NPY file on Windows

The procedure to change the default program in Windows

  • Clicking the NPY with right mouse button will bring a menu from which you should select the Open with option
  • Click Choose another app and then select More apps option
  • To finalize the process, select Look for another app on this PC entry and using the file explorer select the NumPy installation folder. Confirm by checking Always use this app to open NPY files box and clicking OK button.
Associate software with NPY file on Mac

The procedure to change the default program in Mac OS

  • From the drop-down menu, accessed by clicking the file with NPY extension, select Information
  • Proceed to the Open with section. If its closed, click the title to access available options
  • Select NumPy and click Change for all...
  • A message window should appear informing that This change will be applied to all files with NPY extension. By clicking Continue you confirm your selection.

Step 4. Check the NPY for errors

Should the problem still occur after following steps 1-3, check if the NPY file is valid. Being unable to access the file can be related to various issues.

Check NPY file for viruses
1. Verify that the NPY in question is not infected with a computer virus

If the NPY is indeed infected, it is possible that the malware is blocking it from opening. Scan the NPY file as well as your computer for malware or viruses. NPY file is infected with malware? Follow the steps suggested by your antivirus software.

2. Verify that the NPY file’s structure is intact

If the NPY file was sent to you by someone else, ask this person to resend the file to you. During the copy process of the file errors may occurred rendering the file incomplete or corrupted. This could be the source of encountered problems with the file. It could happen the the download process of file with NPY extension was interrupted and the file data is defective. Download the file again from the same source.

3. Ensure that you have appropriate access rights

Some files require elevated access rights to open them. Switch to an account that has required privileges and try opening the NumPy Data Format file again.

4. Make sure that the system has sufficient resources to run NumPy

If the system is under havy load, it may not be able to handle the program that you use to open files with NPY extension. In this case close the other applications.

5. Verify that your operating system and drivers are up to date

Up-to-date system and drivers not only makes your computer more secure, but also may solve problems with NumPy Data Format file. Outdated drivers or software may have caused the inability to use a peripheral device needed to handle NPY files.

Do you want to help?

If you have additional information about the NPY file, we will be grateful if you share it with our users. To do this, use the form here and send us your information on NPY file.

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