Pythonni mustaqil

Nima uchun –22 // 10 ning natijasi –3 ga teng?

1. 
   % j ifoda j bilan bir xil ishoraga ega hamda quyidagicha bo‘lganligi uchun:
   

1. 
   == (i // j) * j + (i % j)
   

Satrni qanday o‘zgartirish mumkin?

Hech qanday, chunki satrlar – o‘zgarmas obyektlar. Aksariyat hollarda turli qismlardan yangi sa-trni tayyorlash yetarli bo‘ladi. Agar juda ham zarur bo‘lsa, io.StringIOdan yoki array modulidan foydalanish mumkin

132

• 
  import io
  

• 
  s = "Hello, world"
  

• 
  sio = io.StringIO(s)
  

• 
  sio.getvalue() 'Hello, world'
  

• 
  sio.seek(7)
  

7

• 
  sio.write("there!")
  

6

• 
  sio.getvalue() 'Hello, there!'
  

• 
  import array
  

• 
  a = array.array('u', s)
  

• 
  print(a)
  

array('u', 'Hello, world')

• 
  a[0] = 'y'
  

• 
  print(a)
  

array('u', 'yello, world')

• 
  a.tounicode() 'yello, world'
  

Funksiya/metodlarni chaqirishda satrlardan qanday foydalanish mumkin?
Buning bir necha metodi mavjud:

• 
  Eng yaxshisi – satrga funksiyani mos qo‘yuvchi lug‘atdan foydalanish kerak. Buning afzal tomoni – satrlar funksiyalarning nomlari bilan aynan bir xil bo‘lishlari shart emasligida.
  

def a():
pass

def b():
pass
dispatch = {'go': a, 'stop': b} # Note lack of parens for funcs dispatch[get_input()]()

• 
  getattr tarkibiy funksiyasidan foydalanish:
  

import foo

getattr(foo, 'bar')()

133

• 
  locals yoki eval dan foydalanish (tavsiya etilmaydi):
  

def myFunc():

print("hello")
fname = "myFunc"
f = locals()[fname]
f()
f = eval(fname)
f()