Merge pull request #1077 from geoffliu/master

[Python3/en] Python3 doc cleanup
This commit is contained in:
Levi Bostian 2015-05-02 20:44:44 -05:00
commit d26900150d

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@ -39,7 +39,7 @@ Note: This article applies to Python 3 specifically. Check out [here](http://lea
# Except division which returns floats by default
35 / 5 # => 7.0
# Result of integer division truncated down both for positive and negative.
# Result of integer division truncated down both for positive and negative.
5 // 3 # => 1
5.0 // 3.0 # => 1.0 # works on floats too
-5 // 3 # => -2
@ -73,8 +73,8 @@ False or True #=> True
# Note using Bool operators with ints
0 and 2 #=> 0
-5 or 0 #=> -5
0 == False #=> True
2 == True #=> False
0 == False #=> True
2 == True #=> False
1 == True #=> True
# Equality is ==
@ -145,7 +145,7 @@ bool({}) #=> False
# Python has a print function
print("I'm Python. Nice to meet you!")
# No need to declare variables before assigning to them.
# No need to declare variables before assigning to them.
# Convention is to use lower_case_with_underscores
some_var = 5
some_var # => 5
@ -186,7 +186,7 @@ li[2:] # => [4, 3]
li[:3] # => [1, 2, 4]
# Select every second entry
li[::2] # =>[1, 4]
# Revert the list
# Return a reversed copy of the list
li[::-1] # => [3, 4, 2, 1]
# Use any combination of these to make advanced slices
# li[start:end:step]
@ -196,7 +196,7 @@ del li[2] # li is now [1, 2, 3]
# You can add lists
# Note: values for li and for other_li are not modified.
li + other_li # => [1, 2, 3, 4, 5, 6]
li + other_li # => [1, 2, 3, 4, 5, 6]
# Concatenate lists with "extend()"
li.extend(other_li) # Now li is [1, 2, 3, 4, 5, 6]
@ -213,7 +213,7 @@ tup = (1, 2, 3)
tup[0] # => 1
tup[0] = 3 # Raises a TypeError
# You can do all those list thingies on tuples too
# You can do most of the list operations on tuples too
len(tup) # => 3
tup + (4, 5, 6) # => (1, 2, 3, 4, 5, 6)
tup[:2] # => (1, 2)
@ -235,15 +235,15 @@ filled_dict = {"one": 1, "two": 2, "three": 3}
# Look up values with []
filled_dict["one"] # => 1
# Get all keys as a list with "keys()".
# We need to wrap the call in list() because we are getting back an iterable. We'll talk about those later.
# Note - Dictionary key ordering is not guaranteed.
# Your results might not match this exactly.
# Get all keys as an iterable with "keys()". We need to wrap the call in list()
# to turn it into a list. We'll talk about those later. Note - Dictionary key
# ordering is not guaranteed. Your results might not match this exactly.
list(filled_dict.keys()) # => ["three", "two", "one"]
# Get all values as a list with "values()". Once again we need to wrap it in list() to get it out of the iterable.
# Note - Same as above regarding key ordering.
# Get all values as an iterable with "values()". Once again we need to wrap it
# in list() to get it out of the iterable. Note - Same as above regarding key
# ordering.
list(filled_dict.values()) # => [3, 2, 1]
@ -281,7 +281,7 @@ some_set = {1, 1, 2, 2, 3, 4} # some_set is now {1, 2, 3, 4}
# Can set new variables to a set
filled_set = some_set
# Add one more item to the set
# Add one more item to the set
filled_set.add(5) # filled_set is now {1, 2, 3, 4, 5}
# Do set intersection with &
@ -328,7 +328,7 @@ for animal in ["dog", "cat", "mouse"]:
print("{} is a mammal".format(animal))
"""
"range(number)" returns a list of numbers
"range(number)" returns an iterable of numbers
from zero to the given number
prints:
0
@ -340,7 +340,7 @@ for i in range(4):
print(i)
"""
"range(lower, upper)" returns a list of numbers
"range(lower, upper)" returns an iterable of numbers
from the lower number to the upper number
prints:
4
@ -458,14 +458,14 @@ all_the_args(**kwargs) # equivalent to foo(a=3, b=4)
all_the_args(*args, **kwargs) # equivalent to foo(1, 2, 3, 4, a=3, b=4)
# Function Scope
# Function Scope
x = 5
def setX(num):
# Local var x not the same as global variable x
x = num # => 43
print (x) # => 43
def setGlobalX(num):
global x
print (x) # => 5
@ -512,8 +512,8 @@ class Human(object):
# Basic initializer, this is called when this class is instantiated.
# Note that the double leading and trailing underscores denote objects
# or attributes that are used by python but that live in user-controlled
# namespaces. Methods(or objects or attributes) like: __init__, __str__,
# __repr__ etc. are called magic methods (or sometimes called dunder methods)
# namespaces. Methods(or objects or attributes) like: __init__, __str__,
# __repr__ etc. are called magic methods (or sometimes called dunder methods)
# You should not invent such names on your own.
def __init__(self, name):
# Assign the argument to the instance's name attribute
@ -600,7 +600,7 @@ def double_numbers(iterable):
# double_numbers.
# Note range is a generator too. Creating a list 1-900000000 would take lot of
# time to be made
# We use a trailing underscore in variable names when we want to use a name that
# We use a trailing underscore in variable names when we want to use a name that
# would normally collide with a python keyword
range_ = range(1, 900000000)
# will double all numbers until a result >=30 found