Python - Data Type Iterate dictionary

Introduction

The following code steps through the keys of a dictionary.

It requests its keys list explicitly:

Demo

D = {'a':1, 'b':2, 'c':3} 
for key in D.keys(): 
    print(key, D[key])

Result

Dictionaries are iterables with an iterator that automatically returns one key at a time in an iteration context:

Demo

D = {'a':1, 'b':2, 'c':3} 
I = iter(D) # w  ww.j av  a 2  s . c  om
print( next(I) )
print( next(I) )
print( next(I) )
print( next(I) )

Result

for loop will use the iteration protocol to grab one key each time through:

Demo

D = {'a':1, 'b':2, 'c':3} 
for key in D: 
     print(key, D[key])

Result

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