Python analytic style

One, List analytic type

List parsing is a pair of brackets outside, which returns a list.

The general form is: [Expr for item ' in itratoble]

Print ([i+1 for I in Range]) #结果: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]

DEF Inc (X):    return X**2print ([Inc (I) for I in Range]) #结果: [0, 1, 4, 9, 16, 25, 36, 49, 64, 81]

print ([I for I in range] if i%2==0]) #结果: [0, 2, 4, 6, 8]

The filter () method takes a function and an iterator object to two parameters, returning a generator object.

List (filter (lambda x:x%2==0,range)) #结果: [0,2,4,6,8]

The map () method takes a function and an iterative object to two parameters, returning a list.

Map (Lambda X:x+1,range) #结果: [1,2,3,4,5,6,,7,8,9,10]

List parsing executes faster than filter () and map ().

Second, generator analytic type

The generator parsing is a pair of parentheses outside, which returns a generator object. It is calculated on demand or delayed.

The general form is: (Expr for item in itratoble)

(X for X in range (ten) if x%2==0)

Three, set analytic type

The set parsing is a pair of curly braces outside, which returns a collection, and it has all the characteristics of the collection.

The general form is: {Expr for item ' in hash-able object}

{x for x in range} #结果: {0,1,2,3,4,5,6,7,8,9}

Four, dictionary analytic style

The dictionary parsing is also a pair of curly braces outside, it requires two expressions, one generates a key, the other generates a value, and two expressions are separated by colons. So it returns a dictionary.

The general form is: {k:v for item in Itratoble}

Python-parsed