Symbol Review Flashcards
and
Logical and. (e.g. True and False == False)
as
Part of the with-as statement. (e.g. with X as Y: pass)
assert
Assert (ensure) that something is true. (e.g. assert False, “Error!”)
break
Stop this loop right now. (e.g. while True: break)
class
Define a class. (e.g. class Person(object))
continue
Don’t process more of the loop, do it again. (e.g. while True: continue)
def
Define a function. (e.g. def X(): pass)
del
Delete from dictionary. (e.g. del X[Y])
elif
Else if condition. (e.g. if: X; elif: Y; else: J)
else
Else condition. (e.g. if: X; elif: Y; else: J)
except
If an exception happens, do this. (e.g. except ValueError, e: print(e))
exec
Run a string as Python. (e.g. exec ‘print(“hello”)’)
finally
Exceptions or not, finally do this no matter what. (e.g. finally: pass)
for
Loop over a collection of things. (e.g. for X in Y: pass)
from
Import specific parts of a module. (e.g. from x import Y)
global
Declare that you want a global variable. (e.g. global X)
if
If condition. (e.g. if: X; elif: Y; else: J)
import
Import a module to use. (e.g. import os)
in
Part of for-loops. Also a test of X in Y. (e.g. for X in Y: pass, 1 in [1] == True)
is
Like == to test equality (e.g. 1 is 1 == True)
lambda
Create a short anonymous function. (e.g. s = lambda y: y ** y; s(3)
not
Logical not. (e.g. not True == False)
or
Logical or. (e.g. True or False == True)
pass
This block is empty. (e.g. def empty(): pass)
Print this string. (e.g. print(‘this string’))
raise
Raise an exception when things go wrong. (e.g. raise ValueError(“No”)
return
Exit the function with a return value. (e.g. def X(): return Y)
try
Try this block, and if exception, go to except. (e.g. try: pass)
while
While loop (e.g. while X: pass)
with
With an expression as a variable do. (e.g. with X as Y: pass)
yield
Pause here and return to caller. (e.g. def X(): yield Y; X().next())
True
True Boolean value.
False
False Boolean value.
None
Represents “nothing” or “no value”. (e.g. x = None)
bytes
Stores bytes, maybe of text, PNG etc files. (e.g. x = b”hello”)
strings
Stores textual information. (e.g. x = “hello”)
numbers
Stores integers. (e.g. i = 100)
floats
Stores decimals. (e.g. i = 10.389)
lists
Stores a list of things. (e.g. k = [1, 2, 3, 4]
dicts
Stores a key=value mapping of things. (e.g. e = {‘x’: 1, ‘y’:2]
\
Blackslash
'
Single-quote
"
Double-quote
\a
Bell
\b
Backspace
\f
Formfeed
\n
Newline
\r
Carriage
\t
Tab
\v
Vertical tab
%d
Decimal integers (not floating point) (e.g. “%d” % 45 == ‘45’)
%i
Decimal integers (not floating point) (e.g. “%i” % 45 == ‘45’)
%o
Octal number (e.g. “%o” % 1000 == ‘1750’)
%u
Unsigned decimal (e.g. “%u” % -1000 = ‘-1000’)
%x
Hexadecimal lowercase (e.g. “%x” % 1000 == ‘3e8’)
%X
Hexadecimal uppercase (e.g. “%X” % 1000 == ‘3E8’)
%e
Exponential notation, lowercase “e” (e.g. “%e” % 1000 == ‘1.000000e+03’)
%E
Exponential notation, uppercase “e” (e.g. “%E” % 1000 == ‘1.000000E+03’)
%f
Floating point real number (e.g. %f % 10.34 == ‘10.340000’)
%F
Floating point real number (e.g. %F % 10.34 == ‘10.340000’)
%g
Either %f or %e, whichever is shorter (e.g. “%g” % 10.34 == ‘10.34’)
%G
Either %F or %E, whichever is shorter (e.g. “%g” % 10.34 == ‘10.34’)
%c
Character format (e.g. “%c” % 34 == ‘ ‘’ ‘)
%r
Repr format (debugging format) (e.g. “%r” % int == “”)
%s
String format (e.g. “%s there” % ‘hi’ == ‘hi there’)
%%
A percent sign (e.g. “%g%%” % 10.34 == ‘10.34%’)
//
Floor division (e.g. 2 // 4 == 0)
%
String interpolate or modulus (e.g. 2 % 4 == 2)
( )
Parentheses
[ ]
List brackets
{ }
Dict curly braces
@
At (decorators) (e.g. @classmethod)
