some python keywords, which are in comments, enclosed in quotation marks to become clear (understandable)

This commit is contained in:
Haydar Kulekci 2013-08-23 00:06:47 +03:00
parent 598fe61e1a
commit 8c1a1d8a7b

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@ -158,19 +158,19 @@ li[2:] #=> [4, 3]
# Omit the end # Omit the end
li[:3] #=> [1, 2, 4] 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] del li[2] # li is now [1, 2, 3]
# You can add lists # You can add lists
li + other_li #=> [1, 2, 3, 4, 5, 6] - Note: li and other_li is left alone 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] 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 1 in li #=> True
# Examine the length with len # Examine the length with `len()`
len(li) #=> 6 len(li) #=> 6
@ -201,37 +201,37 @@ filled_dict = {"one": 1, "two": 2, "three": 3}
# Look up values with [] # Look up values with []
filled_dict["one"] #=> 1 filled_dict["one"] #=> 1
# Get all keys as a list # Get all keys as a list with `keys()`
filled_dict.keys() #=> ["three", "two", "one"] filled_dict.keys() #=> ["three", "two", "one"]
# Note - Dictionary key ordering is not guaranteed. # Note - Dictionary key ordering is not guaranteed.
# Your results might not match this exactly. # 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] filled_dict.values() #=> [3, 2, 1]
# Note - Same as above regarding key ordering. # 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 "one" in filled_dict #=> True
1 in filled_dict #=> False 1 in filled_dict #=> False
# Looking up a non-existing key is a KeyError # Looking up a non-existing key is a KeyError
filled_dict["four"] # 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("one") #=> 1
filled_dict.get("four") #=> None filled_dict.get("four") #=> None
# The get method supports a default argument when the value is missing # The get method supports a default argument when the value is missing
filled_dict.get("one", 4) #=> 1 filled_dict.get("one", 4) #=> 1
filled_dict.get("four", 4) #=> 4 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", 5) #filled_dict["five"] is set to 5
filled_dict.setdefault("five", 6) #filled_dict["five"] is still 5 filled_dict.setdefault("five", 6) #filled_dict["five"] is still 5
# Sets store ... well sets # Sets store ... well sets
empty_set = set() 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]) 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 # Since Python 2.7, {} can be used to declare a set
@ -312,7 +312,7 @@ while x < 4:
# Works on Python 2.6 and up: # Works on Python 2.6 and up:
try: try:
# Use raise to raise an error # Use `raise` to raise an error
raise IndexError("This is an index error") raise IndexError("This is an index error")
except IndexError as e: except IndexError as e:
pass # Pass is just a no-op. Usually you would do recovery here. pass # Pass is just a no-op. Usually you would do recovery here.
@ -322,7 +322,7 @@ except IndexError as e:
## 4. Functions ## 4. Functions
#################################################### ####################################################
# Use def to create new functions # Use `def` to create new functions
def add(x, y): def add(x, y):
print "x is %s and y is %s" % (x, y) print "x is %s and y is %s" % (x, y)
return x + y # Return values with a return statement 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} {"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. # Use * to expand tuples and use ** to expand kwargs.
args = (1, 2, 3, 4) args = (1, 2, 3, 4)
kwargs = {"a": 3, "b": 4} kwargs = {"a": 3, "b": 4}
@ -402,7 +402,7 @@ class Human(object):
# Assign the argument to the instance's name attribute # Assign the argument to the instance's name attribute
self.name = name 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): def say(self, msg):
return "%s: %s" % (self.name, msg) return "%s: %s" % (self.name, msg)