List of Python parsing

List parsing: the creation of a new list based on the original list

List-Resolved build lists, which can also be implemented with a for loop, have the advantage that the list expression is faster than the For loop.

List Resolution Expressions:

Expression One

[Expression for Iter_var in iterable]

Assigns the value in the Iteration object (iterable) to Iter_var and executes the expression

Cases:

>>> a = [1,2,3,4,5]

>>> B = [i**2 for i in a]

>>> b

[1, 4, 9, 16, 25]

Assigns the value in a to I,i execution i**2, the resulting value generates B

Expression two:

[Expression for Iter_var in iterable if condition]

Removes the value from the Iteration object (iterable), assigns to Iter_var if Contion is satisfied, and executes expression

Cases:

>>> a = [1,2,3,4,5]

>>>c = [i**2 for i in a if I% 2 = = 0 and I >=3]

>>> C

[16]

When the value in a is taken out and the value is even and greater than 3, the i**2 is executed, generating C

List of Python parsing