Skip to main content

EEK: A Mac!

  1. Use 'command' or 'apple' key instead of CTRL for copy and paste operations
  2. 'end' is 'command'+'right cursor', 'home' is 'command'+'left cursor'
  3. 'backspace' is Mac 'delete' and 'delete' is Mac 'fn'+'delete'
  4. On firefox (which is what I have used the most) moving the cursor quickly sometimes causes the cursor to have afterimages.
  5. Programs are sometimes installed by dragging the dmg into the applications folder (e.g. when you get Firefox for mac), but are sometimes installed by double clicking the .dmg file (which is basically an archive file of sorts) and then double clicking the .mpkg file which does the actual installation. e.g. for the python installer
  6. Create a shortcut to the applications folder on your desktop - now you can drag applications into this shortcut to install - e.g. firefox/mysql
  7. Screen shots are taken using command+shift+4 or 3 [from here]
  8. Finder doesn't show folders like /tmp, and there is no option to reveal it - you need to type in the folder name after hitting 'go'

Comments

Popular posts from this blog

A note on Python's __exit__() and errors

Python's context managers are a very neat way of handling code that needs a teardown once you are done. Python objects have do have a destructor method ( __del__ ) called right before the last instance of the object is about to be destroyed. You can do a teardown there. However there is a lot of fine print to the __del__ method. A cleaner way of doing tear-downs is through Python's context manager , manifested as the with keyword. class CrushMe: def __init__(self): self.f = open('test.txt', 'w') def foo(self, a, b): self.f.write(str(a - b)) def __enter__(self): return self def __exit__(self, exc_type, exc_val, exc_tb): self.f.close() return True with CrushMe() as c: c.foo(2, 3) One thing that is important, and that got me just now, is error handling. I made the mistake of ignoring all those 'junk' arguments ( exc_type, exc_val, exc_tb ). I just skimmed the docs and what popped out is that you need to return True or

Store numpy arrays in sqlite

Use numpy.getbuffer (or sqlite3.Binary ) in combination with numpy.frombuffer to lug numpy data in and out of the sqlite3 database: import sqlite3, numpy r1d = numpy.random.randn(10) con = sqlite3.connect(':memory:') con.execute("CREATE TABLE eye(id INTEGER PRIMARY KEY, desc TEXT, data BLOB)") con.execute("INSERT INTO eye(desc,data) VALUES(?,?)", ("1d", sqlite3.Binary(r1d))) con.execute("INSERT INTO eye(desc,data) VALUES(?,?)", ("1d", numpy.getbuffer(r1d))) res = con.execute("SELECT * FROM eye").fetchall() con.close() #res -> #[(1, u'1d', <read-write buffer ptr 0x10371b220, size 80 at 0x10371b1e0>), # (2, u'1d', <read-write buffer ptr 0x10371b190, size 80 at 0x10371b150>)] print r1d - numpy.frombuffer(res[0][2]) #->[ 0. 0. 0. 0. 0. 0. 0. 0. 0. 0.] print r1d - numpy.frombuffer(res[1][2]) #->[ 0. 0. 0. 0. 0. 0. 0. 0. 0. 0.] Note that for work where data ty