Python advanced features-iteration and python features

Python advanced features-iteration and python features
Overview

For v in d. values ():

For k, v in d. items ():

For a in 'adfa ':

# Determining whether objects can be iterated

From collections import Iterable

Isinstance ('abc', Iterable)

# Add subscript

For x, y in enumerate ([(1, 1), (2, 3), (4, 5)]):

Explanation 1. Iterative list

>>> d={'a':1,'b':2,'c':3}

# Output values

>>> For v in d. values ():
... Print v
...
1
3
2

# Output both key and value

>>> For k, v in d. items ():... print k, v... # output a 1c 3b 2

2. String Iteration

>>> for a in 'adfa':...      print a... adfa

3. determine whether an object can be iterated

>>> From collections import Iterable # judge whether the string can be iterated >>> isinstance ('abc', Iterable) # Output True
# Determine whether the list can be iterated

>>> Isinstance ([1, 2, 3], Iterable) # Output True
# Determine whether an integer can be iterated

>>> Isinstance (12345, Iterable)
False

4. Implement subscript loop for list

>>> for i,value in enumerate(['a','b','c']):...      print(i,value)... (0, 'a')(1, 'b')(2, 'c')>>> for i,value in enumerate(['a','b','c']):...      print  i,value... 0 a1 b2 c

 

>>> for x,y in [(1,1),(2,3),(4,5)]:...      print x,y... 1 12 34 5

>>> For x, y in enumerate ([(1, 1), (2, 3), (4, 5)]):
... Print x, y
...
0 (1, 1)
1 (2, 3)
2 (4, 5)