"doom %s %d %f" % ("metal", 13, 3.7)
"doom".upper()
"DOOM".lower()
"doom".capitalize()
"value: " + str(66)
'-'.join(['do', 're', 'mi', 'fa']) # do-re-mi-fa
# ["do", "re", "", "mi"]:
'do re mi '.split(' ')
# ["do", "re", "mi"]:
'do re mi '.split()
'foobar'.startswith('foo')
'foobar'.endswith('bar')
q, r = divmod(13, 5)
# Outputs [3, 4]
2**8 #Outputs 256
import datetime
t = datetime.datetime.now( # 2015-05-20 01:00:44 +0800
utc = datetime.datetime.utcnow() # 2015-05-19 17:01:46 UTC
import datetime
t = datetime.datetime.now()
epoch = int(t.strftime("%s"))
Tuples consist of a number of values separated by commas. They are useful for ordered pairs and returning several values from a function.
empty_tuple = ()
single_item_tuple = ("corpse",) # take not of the comma!
my_tuple1 = 33, 666, 'a'
my_tuple2 = (22, 444, 'b')
# accessing a tuple
my_tuple1[1] # returns 33
# define a list
my_list = [6, 5, 'x', 4, 'y']
# access an item list
my_list[0] # returns 6
# slicing
my_list[1:3] # returns [5, 'x']
my_list[2:] # returns ['x', 4, 'y']
my_list[:2] # returns [6, 5]
my_list[2:-1] # returns 6
# length
len(my_list) # returns 5
# sort
my_list.sort() # [4, 5, 6, 'x', 'y']
# add
my_list.append(45) # [4, 5, 6, 'x', 'y', 45]
# return & remove
my_list.pop() # returns 45 [4, 5, 6, 'x', 'y']
my_list.pop(1) # returns 5 [4, 6, 'x', 'y']
# insert
my_list.insert(2, 'z') # [4, 'z', 6, 'x', 'y']
my_list.remove('x') # [4, 'z', 6, 'y']
del my_list[0] # ['z', 6, 'y']
# concatenation
my_list + [0] # returns ['z',6,'y',0] ['z',6,'y']
# finding
9 in my_list # returns True ['z',6,'y']
empty_dict = {}
# Here is a prefilled dictionary
filled_dict = {"one": 1, "two": 2, "three": 3}
# Look up values with []
filled_dict["one"] # => 1
# Get all keys as a list with "keys()"
filled_dict.keys() # => ["three", "two", "one"]
# Note - Dictionary key ordering is not guaranteed.
# Get all values as a list with "values()"
filled_dict.values() # => [3, 2, 1]
# declare a variable
my_var = 6
# if statement. Indentation is significant in python!
# prints "my_var is smaller than 10"
if my_var > 10:
print "my_var is totally bigger than 10."
elif my_var < 10: # elif clause is optional.
print "my_var is smaller than 10."
else: # This is optional too.
print "my_var is indeed 10."
# iterate over a list using 'for'
for song in ["Angel of Death", "Necrophobic", "Altar of Sacrifice"]:
# You can use {0} to interpolate formatted strings.
print "{0} is a track in Reign In Blood".format(song)
for i in range(5):
print i
# iterate using 'while'
x = 0
while x < 5:
print x
x += 1 # shorthand for x = x + 1
Works on Python 2.6 and up:
try:
# Use "raise" to raise an error
raise IndexError("This is an index error")
except IndexError as e:
# Pass is just a no-op. Usually you would do recovery here.
pass
except (TypeError, NameError):
# Multiple exceptions can be handled together, if required.
pass
else:
# Optional clause to the try/except block. Must follow all except blocks
# Runs only if the code in try raises no exceptions
print "All good!"
finally:
# Execute under all circumstances
print "We can clean up resources here"
# Instead of try/finally to cleanup resources you can use a with statement
with open("file.txt") as f:
for line in f:
print line
#!/usr/bin/python
class Song(object):
def __init__(self):
self.artist = "Slayer"
self.title = "Altar of Sacrifice"
self.album = "Reign in Blood"
def showTitle(self):
print self.title
def showArtist(self):
print self.artist
song = Song()
song.showTitle()
song.showArtist()