See Emacs_Reference 

General Commands
     
     
save:     ctrl-x ctrl-s
     
exit:     ctrl-x ctrl-c 
     
cut:     ctrl-k        
     
yank(paste):     ctrl-y 
     
search:     ctrl-s        
     
reduce text size:     ctrl x -        

Window Management
     
split window top/bottom:     ctrl x 2 
     
split window left/right:     ctrl x 3 
     
remove all window splits:     ctrl x 1 
     
close a window:     ctrl x 0 
     
move cursor to next window:     ctrl x o 
     
open directory:     ctrl-x d 

File Management
     
oppen file in window buffer:     ctrl-x ctrl-f 
     
cycle window buffer:     ctrl x right/left arrow 
     
kill buffer:     ctrl x k 
     
new window:     ctrl x 5 2 
     
latex:   ctrl c ctrl c 
     
goto top of file: Alt < 
     
goto a line: type Esc x, then type "goto-line", then hit
     enter, then type the line number 
     
delete a lot of text: Ctrl+Space to mark, move cursor; Ctrl+w to remove text -- use with Alt+> 


Rectangular Cut and Paste

Step 1: Select the rectangle of text to cut
     
     1)Put cursor at upper left corner
     2)Ctrl-Space
     3)Put cursor at bottom rigtht corner
     or, just use the mouse

Step 2: Cut and paste     
     4)ctrl-x r k (to cut)
     5)ctrl-x r y (to paste)

Search and Replace
Esc-% (i.e. Esc+shit+5)
hit enter
type the string you would like to search for
hit enter
type the string you want to replace it with
hit enter
use space bar to step through the replacement.
del - skip one
! - replace all
. - replace 1 and quit

Auto Format
 
Esc q 

Auto tab format entire code file

M-x find-file /path/to/file RET
C-x h                             (M-x mark-whole-buffer)
C-M-\                             (M-x indent-region)


Other

Python bulk group indent: Ctrl-C >   (note ">" requires using the Shift key)