# pydicom.filewriter.write_file_meta_info

pydicom.filewriter.write_file_meta_info(fp: DicomIO, file_meta: FileMetaDataset, enforce_standard: bool = True) → None

  Write the File Meta Information elements in file_meta to fp.

  If enforce_standard is `True` then the file-like fp should be positioned past the 128 byte preamble + 4 byte prefix (which should already have been written).

  DICOM File Meta Information Group Elements

  From the DICOM standard, Part 10, Section 7.1, any DICOM file shall contain a 128-byte preamble, a 4-byte DICOM prefix ‘DICM’ and (at a minimum) the following Type 1 DICOM Elements (from Table 7.1-1):

  - (0002,0000) File Meta Information Group Length, UL, 4

  - (0002,0001) File Meta Information Version, OB, 2

  - (0002,0002) Media Storage SOP Class UID, UI, N

  - (0002,0003) Media Storage SOP Instance UID, UI, N

  - (0002,0010) Transfer Syntax UID, UI, N

  - (0002,0012) Implementation Class UID, UI, N

  If enforce_standard is `True` then (0002,0000) will be added/updated, (0002,0001) and (0002,0012) will be added if not already present and the other required elements will be checked to see if they exist. If enforce_standard is `False` then file_meta will be written as is after minimal validation checking.

  The following Type 3/1C Elements may also be present:

  - (0002,0013) Implementation Version Name, SH, N

  - (0002,0016) Source Application Entity Title, AE, N

  - (0002,0017) Sending Application Entity Title, AE, N

  - (0002,0018) Receiving Application Entity Title, AE, N

  - (0002,0102) Private Information, OB, N

  - (0002,0100) Private Information Creator UID, UI, N

  If enforce_standard is `True` then (0002,0013) will be added/updated.

  Encoding

  The encoding of the File Meta Information shall be Explicit VR Little Endian.

  Parameters:

    - fp (file-like) – The file-like to write the File Meta Information to.

    - file_meta (pydicom.dataset.Dataset) – The File Meta Information elements.

    - enforce_standard (bool) – If `False`, then only the File Meta Information elements already in file_meta will be written to fp. If `True` (default) then a DICOM Standards conformant File Meta will be written to fp.

  Raises:

    - ValueError – If enforce_standard is `True` and any of the required File Meta Information elements are missing from file_meta, with the exception of (0002,0000), (0002,0001) and (0002,0012).

    - ValueError – If any non-Group 2 Elements are present in file_meta.