Bulk Data Python Package

Bulk Data Python Package makes it easy to create and manipulate bulk data files.

• Free software: MIT license
• Documentation: https://bulkdata.readthedocs.io.

Features

• Card objects represent Bulk Data Cards; functionally similar to list objects but can be serialized to a bulk data formatted string representing the card.
• No explicit Bulk Data Card definitions are necessary.
• Deck objects represent a Bulk Data "Deck" containing Bulk Data Cards that can be added, edited, or deleted.
• Loading BDF files containing mixed formatting is supported.

• Bulk Data Formats currently supported:

  • Fixed (same as Small in NASTRAN)
  • Free

Example

This a quick example of using the bulkdata package to update a BDF file.

from bulkdata import Deck, Card

bdf_filename = BDF_DIR + "/example.bdf"

# load Deck from BDF file
with open(bdf_filename) as bdf_file:
    deck = Deck.load(bdf_file)

# CORD2R variables
cid = 1
rid = None
a = [-2.9, 1.0, 0.0]
b = [3.6, 0.0, 1.0]
c = [5.2, 1.0, -2.9]

# create CORD2R card
cord2r = Card("CORD2R")
cord2r.append(cid)
cord2r.append(rid)
cord2r.extend(a)
cord2r.extend(b)
cord2r.extend(c)

# print the CORD2R card in fixed format (the default)
print("-- CORD2R fixed formatting --")
print(cord2r.dumps("fixed"))

# print the CORD2R card in free format
print("-- CORD2R free formatting --")
print(cord2r.dumps("free"))

# add card to the deck
deck.append(cord2r)

# get AEROZ card
aeroz = deck.find_one({"name": "AEROZ"})

print("-- AEROZ before update --")
print(aeroz.dumps())

# update the ACSID field (first one)
aeroz[0] = cid

# update mass and length units fields while we're at it
aeroz[[3, 4]] = ["N", "M"]

print("-- AEROZ after update --")
print(aeroz.dumps())

# dump Deck to update BDF file
with open(bdf_filename, "w") as f:
    deck.dump(f)

Output:

-- CORD2R fixed formatting --
CORD2R  1               -2.9    1.      0.      3.6     0.      1.      +0
+0      5.2     1.      -2.9

-- CORD2R free formatting --
CORD2R,1, ,-2.9,1.,0.,3.6,0.,1.,+0
+0,5.2,1.,-2.9

-- AEROZ before update --
AEROZ           YES     NO      SLIN    IN      400.    300     12000.  +0
+0      10.     0.      0.

-- AEROZ after update --
AEROZ   1       YES     NO      N       M       400.    300     12000.  +0
+0      10.     0.      0.

For a more detailed overview check out the documentation and/or the bulkdata-usage notebook.

TODO

• Add support for BDF files containing INCLUDE statements.
• Add support for Large Field entries
• Add support for BDF files with tabs?

Credits

This package was created with Cookiecutter and the audreyr/cookiecutter-pypackage project template.