Python 不喜欢 FP 的，而且 map / filter 是惰性的，list comprehension不是。循环比 list comprehension...
deftest_for(array): a=[]foriinarray: a.append(i+1)returna dis.dis(test_for)20 BUILD_LIST 03 STORE_FAST 1(a)3 6 SETUP_LOOP 31 (to 40)9LOAD_FAST 0 (array)12GET_ITER>> 13 FOR_ITER 23 (to 39)16 STORE_FAST 2(i)4 19 LOAD_FAST 1(a)22LOAD_ATTR 0 (append)25 LOAD_FAST ...
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# create a new list using list comprehensionsquare_numbers = [num * numfornuminnumbers] print(square_numbers)# Output: [1, 4, 9, 16, 25] Run Code It's much easier to understand list comprehension once you knowPython for loop(). Conditionals in List Comprehension List comprehensions can ...
list comprehension基本语法 例子: 例一[expr for var in collection] 有一个list, squares_1 = [1, 2, 3...100], 要写一个 squares_2 = [1, 4, 9, ..100**2] 用for loop squares = [] for i in range(1, 101): squares.append(i ** 2) ...
【Python学习】- List comprehension A list comprehension allows you to generate this same list in just one line of code. A list comprehension combines the for loop and the creation of new elements into one line, and automatically appends each new element....
This example shows how to create a list of coordinate pairs using nested loops in a list comprehension. Code: # Create a list of coordinate pairs (x, y) for x and y in range(3) pairs = [(x, y) for x in range(3) for y in range(3)] ...
So this list comprehension: >>>short_names=[name.title()fornameinscreencastsiflen(name)<=30] Is equivalent to thisforloop: >>>short_names=[]>>>fornameinscreencasts:...iflen(name)<=30:...short_names.append(name.title())...
在python中,list comprehension(或译为列表推导式)可以很容易的从一个列表生成另外一个列表,从而完成诸如map, filter等的动作,比如: 要把一个字符串数组中的每个字符串都变成大写: names = ["john", "jack", "sean"] result = [] for name in names: ...
Without list comprehension you will have to write aforstatement with a conditional test inside: ExampleGet your own Python Server fruits = ["apple","banana","cherry","kiwi","mango"] newlist = [] forxinfruits: if"a"inx: newlist.append(x) ...