Dasturga Muqaddima 1-bosqich

Python 2 va Python 3 orasidagi farq

Ushbu sahifadan Python 3.x (bu yerda 3.8.3) versiyasini yuklab oling va yuklangan faylni (bu yerda python-3.8.3.exe ) ishga tushiring. Pythonning ikkita bir-biri bilan mos tushmaydigan (incompatible) versiya bor - 2 va 3. Bularning asosiy farqlari quyidagicha:

1. 
   Print funksiyasi
   

Python 2. Kod:
print 'Python', python_version()
print 'Hello, World!'
print('Hello, World!')
print "text", ; print 'print more text on the same line'
Natija:
Python 2.7.6
Hello, World!
Hello, World!
text print more text on the same line
Ko‘rib turganingizdek, Python 2 da print funksiyasidan ikkita usulda ham foydalanish mumkin !
Python 3. Kod:
print('Python', python_version())
print('Hello, World!')


print("some text,", end="")
print(' print more text on the same line')
Natijasi:
Python 3.4.1
Hello, World!
some text, print more text on the same line
Python 3 da print funksiyasini qavssiz ishlatish:
print 'Hello, World!'
Natijasi:
File "", line 1
print 'Hello, World!'
^
SyntaxError: invalid syntax

2. 
   Butun sonlarni bo‘lish
   

Python 2:
print 'Python', python_version()
print '3 / 2 =', 3 / 2
print '3 // 2 =', 3 // 2
print '3 / 2.0 =', 3 / 2.0
print '3 // 2.0 =', 3 // 2.0
Natija:
Python 2.7.6
3 / 2 = 1
3 // 2 = 1
3 / 2.0 = 1.5
3 // 2.0 = 1.0

Python 3:
print('Python', python_version())
print('3 / 2 =', 3 / 2)
print('3 // 2 =', 3 // 2)
print('3 / 2.0 =', 3 / 2.0)
print('3 // 2.0 =', 3 // 2.0)

Natija:
Python 3.4.1
3 / 2 = 1.5
3 // 2 = 1
3 / 2.0 = 1.5
3 // 2.0 = 1.0

3. 
   Unicode
   

Python 2 ASCII str() satr turiga, alohida unicode() turiga ega, lekin byte() turiga ega emas. Python 3 unicode(), byte() va bityarray() turlariga ega.

4. 
   Xrange()
   

Python 2dan farqli o’laroq Python 3da xrange() funksiyasi yo’q, unda range() xrange() kabi ishlaydi.

5. 
   next() va .next()
   

Python 2 da ikkalasidan next() funksiyasi va .next() metodidan foydalanish mumkin. Python 3 da faqat next() funksiyasi aniqlangan, .next() metodidan foydalanish xatoni yuzaga keltiradi.
Python 2. Kod va natijasi:
print 'Python', python_version()


my_generator = (letter for letter in 'abcdefg')


next(my_generator)
my_generator.next()
Python 2.7.6


'b'

Python 3. Kod va natijasi:

print('Python', python_version())


my_generator = (letter for letter in 'abcdefg')


next(my_generator)
Python 3.4.1


'a'

Ko‘proq ma’lumotni ushbu sahifadan olish mumkin: https://www.geeksforgeeks.org/important-differences-between-python-2-x-and-python-3-x-with-examples/

2-qism

1-savol
Kompyuteringizdagi terminalda Python interaktiv tarjimonini (boshqacha nomi Python interaktiv rejimi) ishga tushiring. Keyin cake so‘zini kiritib ko‘ring:
>>> cake
Nima bo‘ldi?



2-savol
Endi yana urinib ko‘ring, lekin so‘zni qo‘shtirnoq ichiga qo‘ying:
>>> "cake"
Nima bo‘ldi?


3-savol
Endi ushbu ikki qatorni bajarishga urinib ko‘ring:
>>> cake = "yummy"
>>> cake
Nima bo‘ldi?


4-savol
Endi ushbu qatorni bajarishga urinib ko‘ring:
>>> "cake" = "yummy"
Nima bo‘ldi?

Izoh: literalga tayinlab bo‘lmaydi degan xato xabari chiqadi.

5-savol
Quyida kod berilgan:
amy = turtle.Turtle()
amy.color("blue")
distance = 50
amy.forward(distance)
amy.right(90)
Kodning ushbu qismlaridan qaysi biri o‘zgaruvchi nomlari (a.k.a. identifikatorlari) va literallar?

Izoh: sonlar va satrlar literallar.

3-qism

1-savol
Quyida "len" funksiyasi bilan terminalingizda sinab ko‘rishingiz mumkin bo‘lgan turli xil misollar bor.
Siz ularni sinab ko‘rayotib, quyidagi savollarni yodda saqlang:
Uzunlikni hisoblashda bo‘shliq (space)lar hisoblanadimi?
O‘zgaruvchiga satr tayinlab, keyin o‘zgaruvchida "len" metodidan foydalana olasizmi?
Butun sonning uzunligini olish mumkinmi?