This is particularly useful for working with very large arrays that cannot fit entirely into physical memory. This has minimal impact on smaller files as well, though some operations, such as reading the array data sequentially, may incur some additional overhead.
On 32-bit systems arrays larger than 2-3 GB cannot be mmap’d (which is fine, because by that point you’re likely to run out of physical memory anyways), but 64-bit systems are much less limited in this respect.
Keywords are usually unique within a header, except in a few special cases.
The header attribute is a Header instance, another Py FITS object.
Sometimes they don’t often give you warning or message. Well, try not to do this to much, and definitely not by mentioning more than one people in one comment.
Instagram today has become a treacherous land to navigate through, it has more traps and mines than Afghanistan after the war. It sucks I know, but as I mention at the beginning of this post, this is the new paranoid Instagram. DO be careful when you use Like or Follow Bot services.
It should be noted that Py FITS is using zero-based indexing when referring to HDUs and header cards, though the FITS standard (which was designed with FORTRAN in mind) uses one-based indexing.
In Py FITS versions prior to v3.4.0 this was function will seamlessly open FITS files that have been compressed with gzip, bzip2 or pkzip.
FITS (Flexible Image Transport System) is a portable file standard widely used in the astronomy community to store images and tables. Support for Python 3.0 through 3.2 is deprecated, but Python 3.3 and above are fully supported. Information about numpy can be found at: Py FITS’ source code is mostly pure Python, but includes an optional C module which wraps CFITSIO for compression support.
The latest source distributions and binary installers for Windows can be downloaded from: This will install Py FITS in the system’s Python site-packages directory.
The data may or may not be accessible depending on whether the data are touched and if they are memory-mapped, see later chapters for detail.
argument that allows the array data of each HDU to be accessed with mmap, rather than being read into memory all at once.