python practice sets

areacalc.py

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+#standard input
+# name = input('Enter your first name:')
+# print ('Hello' + name)
+
+#radius and area are examples of variables
+
+#Area of a circle
+radius = int(input('Enter radius:'))
+area = 3.142 * radius ** 2
+print(f'The area of the circle is {area}')

classes.py

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+class Employee:
+
+    def __init__(self, name, salary, duration):
+        self.name = name
+        self.salary = salary
+        self.duration = duration
+
+
+    def time_spent(self):
+        return self.salary * self.duration
+
+kyanda = Employee('kyanda', 1000, 10)
+print(f'Employee name: {kyanda.name}')
+print(f'Salary: {kyanda.salary}')
+print(f'time spent at work: {kyanda.duration}')
+print(kyanda.time_spent())
+
+# instance level attributes
+# class level attributes
+# @classmethods
+# @staticmethods

comprehension.py

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+# list comprehension
+
+#double prize money weekend bonanza
+prizes = [5, 10, 50, 100, 1000]
+
+#normal way
+dbl_prizes = []
+for prize in prizes:
+    dbl_prizes.append(prize * 2)
+print(dbl_prizes)
+
+#list comprehension way
+dbl_prizes = [ prize * 2 for prize in prizes ]
+print(dbl_prizes)

controlflow.py

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+age = int(input('How old are you?'))
+
+if age < 10:
+    print('You are young!')
+
+elif age <25:
+    print('You are a youth!')
+
+else:
+    print('gundi okuze!!!')
+
+#operators > < => =<
+
+#comparison operators ==  !=
+
+menu = input('do you need a menu? (y/n)')
+
+if menu == 'y':
+    print('here is the menu and you get a free soda!')
+
+else:
+    print('save money and come back!')

date.py

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+#dates, times, datetimes, timezones, timedeltas
+#naive date times - doesnt include time zone and day light savings
+#aware date time - includes time zones and day light savings
+
+import datetime
+
+d = datetime.date(2019, 11, 3)
+print(d)
+
+currentDate = datetime.date.today()
+print(currentDate)
+print(currentDate.year)
+
+#timedelta - difference between two dates and time
+#adding gets future date whereas subtracting gets past date
+tdelta = datetime.timedelta(days=30)
+print(f'Next date for paying subscription is: {currentDate + tdelta}')
+
+#TIME
+t = datetime.time(10, 30, 10, 10000)
+print(t)
+
+
+#DATETIME
+dt = datetime.datetime(2019, 11, 3, 10, 30, 10, 10000)
+tdelta2 = datetime.timedelta(days=30)
+print(dt)
+#calculate date difference with time
+print(dt + tdelta2)
+
+dt_today = datetime.datetime.today()
+print(dt_today)     # prints current datetime with no timezone
+
+
+# thou it is recommended to use the PYTZ LIBRARY IF YOU ARE DEALING WITH TIMEZONE
+#pip install pytz
+
+import pytz
+dt_tz = datetime.datetime(2019, 11, 4, 8, 53, 4, tzinfo=pytz.UTC)
+print(dt_tz)
+
+dt_utcnow = datetime.datetime.now(tz=pytz.UTC)
+print(dt_utcnow)
+
+# converting this timezone to another
+dt_kampala = dt_utcnow.astimezone(pytz.timezone('Africa/Kampala'))
+print(f'Kampala timezone is: {dt_kampala}')
+
+# format code ---- python datetime documentation
+print(dt_kampala.strftime('%B %d, %Y'))
+
+# list of timezones
+# for tz in pytz.all_timezones:
+#     print(tz)

decorators.py

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+#used a lot in django @login_required @permission_required
+
+def permission_dec(func):
+
+    def func_wrapper():
+        #code before function
+        print('please login to see secrets and list of presidents')
+        func()
+        #code after function
+        print('you are logged in and permitted')
+
+    return func_wrapper
+
+@permission_dec
+def secrets():
+    print('here are Ugandan secrets since 1900')
+
+secrets()
+
+@permission_dec
+def view_ugandan_presidents():
+    print("Uganda's presidents: Museveni Yoweri, Ignatius Musaazi, Tito Okello, Obote Milton ...")
+
+view_ugandan_presidents()

functions.py

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+def greet():
+    print("hello there!")
+
+greet()
+
+# return keyword

loops.py

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+#for loop
+fruits = ['apple', 'pineapple', 'water melon', 'mango', 'straw berry']
+
+for fruit in fruits:
+    print(fruit)
+
+
+for fruit in fruits[0:2]:
+    print(fruit)
+
+#useful in django for outputting content
+# break keyword
+#while loop
+# continue keyword

modules.py

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+# modules and packages
+# modules - pieces of code split into logical sections. these python files can be imported and reused
+# packages - a collection of modules
+
+#Example:
+from classes import Employee
+
+chiya = Employee('chiya', 2000, 5)
+print(f'Employee name: {chiya.name}')
+print(f'Salary: {chiya.salary}')
+print(f'time spent at work: {chiya.duration}')
+print(chiya.time_spent())
+
+
+#Package
+#setup:
+# create folder
+# add __init__.py file
+#add other py files in folder

projects/dl_img.py

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+import urllib.request
+
+def dl_jpg(url, file_path, file_name):
+    full_path = file_path + file_name + '.jpg'
+    urllib.request.urlretrieve(url, full_path)
+
+url = input('Enter image url: ')
+file_name = input('Enter file name to save as: ')
+dl_jpg(url, 'images/', file_name)
+
+
+#download images like in the social network movie
+#face mash
+
+#urllib documentation
+#video downloads eg from youtube

stringsformat.py

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+num1= 3.142
+num2= 10.234567
+
+#previously areacalc
+#print('num1 is:', num1, 'num2 is:', num2)
+
+
+# Format method
+print('num1 is {0} and num2 is {1}'.format(num1,num2))