Character / Command * What it's called * What it does * example * example2
pydoc <something> # pydoc gives you the manual page for something you want to know about in python pydoc sys
help() # help function use when running python to find help on an object
print() # print function prints to the console whatever is next print(“Hello World!”) print(1 + 2)
" " # double quotes starts and ends a string print(“Hello World!”)
' ' # single quotes starts and ends a string print("Hello World!")
= # equals assigns values to a variable or function count = 10 i, j, k, numbers = initialize()
# pound comment; blocks out the line from being read by the interpreter # This is a comment and won't do anything
; # semi-colon let's you separate multiple lines of code on one line from sys import argv; from os.path import exists; script, from_file, to_file = argv
- # colon used for defining things like in functions; tells python you are going to create a new "block" of code" followed by a new line with 4 indented spaces and then code. def some_function()
, # comma separates strings from variables print "The script is called:", script
- # plus adds 2+2 equals 4
- # minus subtracts etc.
/ # slash divides, allows you to continue a line of code on multiple lines etc.
- # asterik multiplies, wild card from ex25 import *
% # 1. percent gives the remainder of a divisor 7 % 6 returns 1
% # 2. String Fornatter converts something to something in a string http://docs.python.org/2/library/stdtypes.html#string-formatting-operations
"%d, %r, %s # escape characters let's you insert the contents of a variable into a string. %d is for display, %r is for debugging, %s is for inserting / converting to a string. there are others as well... print "You have this many %d potatoes." % potatoes
( ) # paranthesis for multiple escape character variables, functions print("Some string {0} {1}".format(variable1, variable2)) some_function()
< # greater than comparison operator if buses > cars: print "Too many buses."
> # less than comparison operator
<= # greater than or equal to comparison operator
>= # less than or equal to comparison operator
== # is equal to comparison operator
!= # does not equal comparison operator
_ # underscore charcter generally used instead of spaces number_passengers
# backslash let's you "escape" certain characters in python print "I have a "stupid" cat." print "I am 5'8" tall."
n # newline character (backslash n) inserts a new line
t # tab inserts a tab print(""" I'll do a list: ntbeer ntchips nt*salsa """)
""" # triple double quotes lets you type a comment on mulitple lines, as long as you have """ at the begining and end
"""This is some code that does blah blah blah"""
raw_input() # raw input (built in function) takes input in the form a string from the user you can prompt the user by doing
: raw_input("user give me some data") var = raw_input("> ")
input() # input function (built in) takes input in the form of a integer from the user age = input("What's your age? ")
import # import statement adds native python modules from sys import argv
sys # sys module provides access to some objects used or maintained by the interpreter and to functions that interact
strongly with the interpreter from sys import argv
argv # argument variable see pydoc sys script, filename = argv
os.path # path module
exists # exists command returns true / false if a file exists or not
int() # convert to integer function takes a number and makes it an integer int(3.33) would return 3
float() # convert to a floating point number "" makes it a float float(3) would return 3.0
open() # open function built in function for opening files text = open(some_file)
read() # read function reads the contents of the script. see pydoc file print(text.read())
close() # close function closes the file text.close()
write(stuff) # write function writes stuff to the file text.write(stuff)
truncate() # truncate function empties the file text.truncate()
seek() # seek takes you to specific line in a file def rewind(f): f.seek(0)
range() # range adds a range of integers to a list. range(1,6) will return 0, 1, 2, 3, 4, 5. You can also specify the step in the 3rd number eg: range(1,6,2) will return 0, 2, 4 <<<
append() #append appends object(s) to the end of the list
. # period, dot *lets you call functions on variables or string connect multiple functions: open(to_file, 'w' ).write(indata) OR output.close()
def # define *defines a function: def this_function(some_parameter):
return # return *returns something to the console from within a funciton
[ ] # brackets *for containing lists fruit = ['apples', 'oranges', bananas'] coins = [1, 5, 10, 25]
Thank you clhenrick