There is a hotkey, mapped by default to Ctrl+Shift+NUM_KEYPAD_DIVIDE.
You can change it to something else via Window -> Preferences, search for “Keys”, then for “Collapse All”.
To open all code blocks the shortcut is Ctrl+Shift+NUM_KEYPAD_MULTIPLY.
In the Eclipse extension PyDev, close all code blocks is
Ctrl + 9
To open all blocks, is Ctrl + 0