diff options
Diffstat (limited to 'python.html.markdown')
| -rw-r--r-- | python.html.markdown | 34 |
1 files changed, 17 insertions, 17 deletions
diff --git a/python.html.markdown b/python.html.markdown index f0b74d08..bad9a360 100644 --- a/python.html.markdown +++ b/python.html.markdown @@ -93,8 +93,8 @@ not False #=> True # None is an object None #=> None -# Don't use the equality `==` symbol to compare objects to None -# Use `is` instead +# Don't use the equality "==" symbol to compare objects to None +# Use "is" instead "etc" is None #=> False None is None #=> True @@ -158,19 +158,19 @@ li[2:] #=> [4, 3] # Omit the end li[:3] #=> [1, 2, 4] -# Remove arbitrary elements from a list with del +# Remove arbitrary elements from a list with "del" del li[2] # li is now [1, 2, 3] # You can add lists li + other_li #=> [1, 2, 3, 4, 5, 6] - Note: li and other_li is left alone -# Concatenate lists with extend +# Concatenate lists with "extend()" li.extend(other_li) # Now li is [1, 2, 3, 4, 5, 6] -# Check for existence in a list with in +# Check for existence in a list with "in" 1 in li #=> True -# Examine the length with len +# Examine the length with "len()" len(li) #=> 6 @@ -201,37 +201,37 @@ filled_dict = {"one": 1, "two": 2, "three": 3} # Look up values with [] filled_dict["one"] #=> 1 -# Get all keys as a list +# Get all keys as a list with "keys()" filled_dict.keys() #=> ["three", "two", "one"] # Note - Dictionary key ordering is not guaranteed. # Your results might not match this exactly. -# Get all values as a list +# Get all values as a list with "values()" filled_dict.values() #=> [3, 2, 1] # Note - Same as above regarding key ordering. -# Check for existence of keys in a dictionary with in +# Check for existence of keys in a dictionary with "in" "one" in filled_dict #=> True 1 in filled_dict #=> False # Looking up a non-existing key is a KeyError filled_dict["four"] # KeyError -# Use get method to avoid the KeyError +# Use "get()" method to avoid the KeyError filled_dict.get("one") #=> 1 filled_dict.get("four") #=> None # The get method supports a default argument when the value is missing filled_dict.get("one", 4) #=> 1 filled_dict.get("four", 4) #=> 4 -# Setdefault method is a safe way to add new key-value pair into dictionary +# "setdefault()" method is a safe way to add new key-value pair into dictionary filled_dict.setdefault("five", 5) #filled_dict["five"] is set to 5 filled_dict.setdefault("five", 6) #filled_dict["five"] is still 5 # Sets store ... well sets empty_set = set() -# Initialize a set with a bunch of values +# Initialize a "set()" with a bunch of values some_set = set([1,2,2,3,4]) # some_set is now set([1, 2, 3, 4]) # Since Python 2.7, {} can be used to declare a set @@ -284,7 +284,7 @@ for animal in ["dog", "cat", "mouse"]: print "%s is a mammal" % animal """ -`range(number)` returns a list of numbers +"range(number)" returns a list of numbers from zero to the given number prints: 0 @@ -312,7 +312,7 @@ while x < 4: # Works on Python 2.6 and up: try: - # Use raise to raise an error + # Use "raise" to raise an error raise IndexError("This is an index error") except IndexError as e: pass # Pass is just a no-op. Usually you would do recovery here. @@ -322,7 +322,7 @@ except IndexError as e: ## 4. Functions #################################################### -# Use def to create new functions +# Use "def" to create new functions def add(x, y): print "x is %s and y is %s" % (x, y) return x + y # Return values with a return statement @@ -359,7 +359,7 @@ all_the_args(1, 2, a=3, b=4) prints: {"a": 3, "b": 4} """ -# When calling functions, you can do the opposite of varargs/kwargs! +# When calling functions, you can do the opposite of args/kwargs! # Use * to expand tuples and use ** to expand kwargs. args = (1, 2, 3, 4) kwargs = {"a": 3, "b": 4} @@ -402,7 +402,7 @@ class Human(object): # Assign the argument to the instance's name attribute self.name = name - # An instance method. All methods take self as the first argument + # An instance method. All methods take "self" as the first argument def say(self, msg): return "%s: %s" % (self.name, msg) |