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mirror of https://github.com/adambard/learnxinyminutes-docs.git synced 2025-08-12 01:34:19 +02:00

Made the file pep8 compliant (#2601)

Actually nearly compliant, I ran `pep8 code.py --ignore=E402,E501,E712`
This commit is contained in:
David Haberthür
2016-12-20 15:04:12 +01:00
committed by ven
parent 919e44f843
commit 4737819e5d

View File

@@ -5,6 +5,7 @@ contributors:
- ["Amin Bandali", "http://aminbandali.com"] - ["Amin Bandali", "http://aminbandali.com"]
- ["Andre Polykanine", "https://github.com/Oire"] - ["Andre Polykanine", "https://github.com/Oire"]
- ["evuez", "http://github.com/evuez"] - ["evuez", "http://github.com/evuez"]
- ["habi", "http://github.com/habi"]
filename: learnpython.py filename: learnpython.py
--- ---
@@ -34,9 +35,8 @@ Python 3 tutorial.
as comments as comments
""" """
#################################################### ####################################################
## 1. Primitive Datatypes and Operators # 1. Primitive Datatypes and Operators
#################################################### ####################################################
# You have numbers # You have numbers
@@ -65,6 +65,7 @@ Python 3 tutorial.
# Note that we can also import division module(Section 6 Modules) # Note that we can also import division module(Section 6 Modules)
# to carry out normal division with just one '/'. # to carry out normal division with just one '/'.
from __future__ import division from __future__ import division
11 / 4 # => 2.75 ...normal division 11 / 4 # => 2.75 ...normal division
11 // 4 # => 2 ...floored division 11 // 4 # => 2 ...floored division
@@ -170,14 +171,15 @@ bool("") # => False
#################################################### ####################################################
## 2. Variables and Collections # 2. Variables and Collections
#################################################### ####################################################
# Python has a print statement # Python has a print statement
print "I'm Python. Nice to meet you!" # => I'm Python. Nice to meet you! print "I'm Python. Nice to meet you!" # => I'm Python. Nice to meet you!
# Simple way to get input data from console # Simple way to get input data from console
input_string_var = raw_input("Enter some data: ") # Returns the data as a string input_string_var = raw_input(
"Enter some data: ") # Returns the data as a string
input_var = input("Enter some data: ") # Evaluates the data as python code input_var = input("Enter some data: ") # Evaluates the data as python code
# Warning: Caution is recommended for input() method usage # Warning: Caution is recommended for input() method usage
# Note: In python 3, input() is deprecated and raw_input() is renamed to input() # Note: In python 3, input() is deprecated and raw_input() is renamed to input()
@@ -194,7 +196,6 @@ some_other_var # Raises a name error
# Equivalent of C's '?:' ternary operator # Equivalent of C's '?:' ternary operator
"yahoo!" if 3 > 2 else 2 # => "yahoo!" "yahoo!" if 3 > 2 else 2 # => "yahoo!"
# Lists store sequences # Lists store sequences
li = [] li = []
# You can start with a prefilled list # You can start with a prefilled list
@@ -263,7 +264,6 @@ li.index(7) # Raises a ValueError as 7 is not in the list
# Examine the length with "len()" # Examine the length with "len()"
len(li) # => 6 len(li) # => 6
# Tuples are like lists but are immutable. # Tuples are like lists but are immutable.
tup = (1, 2, 3) tup = (1, 2, 3)
tup[0] # => 1 tup[0] # => 1
@@ -283,7 +283,6 @@ g = 4, 5, 6 # => (4, 5, 6)
# Now look how easy it is to swap two values # Now look how easy it is to swap two values
e, d = d, e # d is now 5 and e is now 4 e, d = d, e # d is now 5 and e is now 4
# Dictionaries store mappings # Dictionaries store mappings
empty_dict = {} empty_dict = {}
# Here is a prefilled dictionary # Here is a prefilled dictionary
@@ -327,7 +326,6 @@ filled_dict["four"] = 4 # now, filled_dict["four"] => 4
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 (which are like lists but can contain no duplicates) # Sets store ... well sets (which are like lists but can contain no duplicates)
empty_set = set() empty_set = set()
# Initialize a "set()" with a bunch of values # Initialize a "set()" with a bunch of values
@@ -367,7 +365,7 @@ filled_set | other_set # => {1, 2, 3, 4, 5, 6}
#################################################### ####################################################
## 3. Control Flow # 3. Control Flow
#################################################### ####################################################
# Let's just make a variable # Let's just make a variable
@@ -382,7 +380,6 @@ elif some_var < 10: # This elif clause is optional.
else: # This is optional too. else: # This is optional too.
print "some_var is indeed 10." print "some_var is indeed 10."
""" """
For loops iterate over lists For loops iterate over lists
prints: prints:
@@ -453,7 +450,7 @@ with open("myfile.txt") as f:
#################################################### ####################################################
## 4. Functions # 4. Functions
#################################################### ####################################################
# Use "def" to create new functions # Use "def" to create new functions
@@ -461,6 +458,7 @@ def add(x, y):
print "x is {0} and y is {1}".format(x, y) print "x is {0} and y is {1}".format(x, y)
return x + y # Return values with a return statement return x + y # Return values with a return statement
# Calling functions with parameters # Calling functions with parameters
add(5, 6) # => prints out "x is 5 and y is 6" and returns 11 add(5, 6) # => prints out "x is 5 and y is 6" and returns 11
@@ -473,13 +471,16 @@ add(y=6, x=5) # Keyword arguments can arrive in any order.
def varargs(*args): def varargs(*args):
return args return args
varargs(1, 2, 3) # => (1, 2, 3) varargs(1, 2, 3) # => (1, 2, 3)
# You can define functions that take a variable number of # You can define functions that take a variable number of
# keyword args, as well, which will be interpreted as a dict by using ** # keyword args, as well, which will be interpreted as a dict by using **
def keyword_args(**kwargs): def keyword_args(**kwargs):
return kwargs return kwargs
# Let's call it to see what happens # Let's call it to see what happens
keyword_args(big="foot", loch="ness") # => {"big": "foot", "loch": "ness"} keyword_args(big="foot", loch="ness") # => {"big": "foot", "loch": "ness"}
@@ -488,6 +489,8 @@ keyword_args(big="foot", loch="ness") # => {"big": "foot", "loch": "ness"}
def all_the_args(*args, **kwargs): def all_the_args(*args, **kwargs):
print args print args
print kwargs print kwargs
""" """
all_the_args(1, 2, a=3, b=4) prints: all_the_args(1, 2, a=3, b=4) prints:
(1, 2) (1, 2)
@@ -502,6 +505,7 @@ all_the_args(*args) # equivalent to foo(1, 2, 3, 4)
all_the_args(**kwargs) # equivalent to foo(a=3, b=4) 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) all_the_args(*args, **kwargs) # equivalent to foo(1, 2, 3, 4, a=3, b=4)
# you can pass args and kwargs along to other functions that take args/kwargs # you can pass args and kwargs along to other functions that take args/kwargs
# by expanding them with * and ** respectively # by expanding them with * and ** respectively
def pass_all_the_args(*args, **kwargs): def pass_all_the_args(*args, **kwargs):
@@ -509,29 +513,36 @@ def pass_all_the_args(*args, **kwargs):
print varargs(*args) print varargs(*args)
print keyword_args(**kwargs) print keyword_args(**kwargs)
# Function Scope # Function Scope
x = 5 x = 5
def set_x(num): def set_x(num):
# Local var x not the same as global variable x # Local var x not the same as global variable x
x = num # => 43 x = num # => 43
print x # => 43 print x # => 43
def set_global_x(num): def set_global_x(num):
global x global x
print x # => 5 print x # => 5
x = num # global var x is now set to 6 x = num # global var x is now set to 6
print x # => 6 print x # => 6
set_x(43) set_x(43)
set_global_x(6) set_global_x(6)
# Python has first class functions # Python has first class functions
def create_adder(x): def create_adder(x):
def adder(y): def adder(y):
return x + y return x + y
return adder return adder
add_10 = create_adder(10) add_10 = create_adder(10)
add_10(3) # => 13 add_10(3) # => 13
@@ -555,12 +566,11 @@ filter(lambda x: x > 5, [3, 4, 5, 6, 7]) # => [6, 7]
#################################################### ####################################################
## 5. Classes # 5. Classes
#################################################### ####################################################
# We subclass from object to get a class. # We subclass from object to get a class.
class Human(object): class Human(object):
# A class attribute. It is shared by all instances of this class # A class attribute. It is shared by all instances of this class
species = "H. sapiens" species = "H. sapiens"
@@ -575,7 +585,6 @@ class Human(object):
# Initialize property # Initialize property
self.age = 0 self.age = 0
# 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 "{0}: {1}".format(self.name, msg) return "{0}: {1}".format(self.name, msg)
@@ -637,17 +646,18 @@ i.age # => 42
del i.age del i.age
i.age # => raises an AttributeError i.age # => raises an AttributeError
#################################################### ####################################################
## 6. Modules # 6. Modules
#################################################### ####################################################
# You can import modules # You can import modules
import math import math
print math.sqrt(16) # => 4 print math.sqrt(16) # => 4
# You can get specific functions from a module # You can get specific functions from a module
from math import ceil, floor from math import ceil, floor
print ceil(3.7) # => 4.0 print ceil(3.7) # => 4.0
print floor(3.7) # => 3.0 print floor(3.7) # => 3.0
@@ -657,9 +667,11 @@ from math import *
# You can shorten module names # You can shorten module names
import math as m import math as m
math.sqrt(16) == m.sqrt(16) # => True math.sqrt(16) == m.sqrt(16) # => True
# you can also test that the functions are equivalent # you can also test that the functions are equivalent
from math import sqrt from math import sqrt
math.sqrt == m.sqrt == sqrt # => True math.sqrt == m.sqrt == sqrt # => True
# Python modules are just ordinary python files. You # Python modules are just ordinary python files. You
@@ -669,8 +681,10 @@ math.sqrt == m.sqrt == sqrt # => True
# You can find out which functions and attributes # You can find out which functions and attributes
# defines a module. # defines a module.
import math import math
dir(math) dir(math)
# If you have a Python script named math.py in the same # If you have a Python script named math.py in the same
# folder as your current script, the file math.py will # folder as your current script, the file math.py will
# be loaded instead of the built-in Python module. # be loaded instead of the built-in Python module.
@@ -679,7 +693,7 @@ dir(math)
#################################################### ####################################################
## 7. Advanced # 7. Advanced
#################################################### ####################################################
# Generators # Generators
@@ -693,6 +707,7 @@ def double_numbers(iterable):
for i in iterable: for i in iterable:
double_arr.append(i + i) double_arr.append(i + i)
# Running the following would mean we'll double all values first and return all # Running the following would mean we'll double all values first and return all
# of them back to be checked by our condition # of them back to be checked by our condition
for value in double_numbers(range(1000000)): # `test_non_generator` for value in double_numbers(range(1000000)): # `test_non_generator`
@@ -700,12 +715,14 @@ for value in double_numbers(range(1000000)): # `test_non_generator`
if value > 5: if value > 5:
break break
# We could instead use a generator to "generate" the doubled value as the item # We could instead use a generator to "generate" the doubled value as the item
# is being requested # is being requested
def double_numbers_generator(iterable): def double_numbers_generator(iterable):
for i in iterable: for i in iterable:
yield i + i yield i + i
# Running the same code as before, but with a generator, now allows us to iterate # Running the same code as before, but with a generator, now allows us to iterate
# over the values and doubling them one by one as they are being consumed by # over the values and doubling them one by one as they are being consumed by
# our logic. Hence as soon as we see a value > 5, we break out of the # our logic. Hence as soon as we see a value > 5, we break out of the
@@ -732,13 +749,13 @@ values = (-x for x in [1,2,3,4,5])
gen_to_list = list(values) gen_to_list = list(values)
print(gen_to_list) # => [-1, -2, -3, -4, -5] print(gen_to_list) # => [-1, -2, -3, -4, -5]
# Decorators # Decorators
# in this example beg wraps say # in this example beg wraps say
# Beg will call say. If say_please is True then it will change the returned # Beg will call say. If say_please is True then it will change the returned
# message # message
from functools import wraps from functools import wraps
def beg(target_function): def beg(target_function):
@wraps(target_function) @wraps(target_function)
def wrapper(*args, **kwargs): def wrapper(*args, **kwargs):
@@ -749,11 +766,13 @@ def beg(target_function):
return wrapper return wrapper
@beg @beg
def say(say_please=False): def say(say_please=False):
msg = "Can you buy me a beer?" msg = "Can you buy me a beer?"
return msg, say_please return msg, say_please
print say() # Can you buy me a beer? print say() # Can you buy me a beer?
print say(say_please=True) # Can you buy me a beer? Please! I am poor :( print say(say_please=True) # Can you buy me a beer? Please! I am poor :(
``` ```