Python Iterations

gistfile1.py

#Plain Lists
list = ["a", "b", "c"]
for v in list:
  print v
#Outputs:
#a
#b
#c

#Dictionaries, only by keys
dict = {"a": 1, "b": 2, "c": 3}
for v in dict:
  print v
#Outputs:
#a
#b
#c

#Dictionaries, with keys, printing the associated value
dict = {"a": 1, "b": 2, "c": 3}
for v in dict:
  print v
  print dict[v]
#Outputs:
#a
#1
#c
#3
#b
#2
#This is equivalent to for k in dict.keys():..., but much faster.

#Dictionaries, with unpacked keys and values
dict = {"a": 1, "b": 2, "c": 3}
for k, v in dict.items(): #or .iteritems() in Python <3.x
  print k
  print v
#Outputs:
#a
#1
#c
#3
#b
#2

#Dictionaries, by accessing only the values
dict = {"a": 1, "b": 2, "c": 3}
for v in dict.itervalues():
  print v
#Outputs:
#1
#2
#3

#Getting a list of keys from a dictionary
dict = {"a": 1, "b": 2, "c": 3}
print dict.keys()
#Outputs:
#['a', 'c', 'b']

#Getting a list of values from a dictionary
dict = {"a": 1, "b": 2, "c": 3}
print dict.values()
#Outputs:
#[1, 3, 2]