尝试通过连接变量名称并仅打印一列来从 3D 数组打印

Question

jEngines = [
            [["Aerotech 54mm Motor (J1799N)"], ["0.6"], ["1799"], ["1090"], ["540"]],
            [["Cesaroni 54mm Motor (J760)"], ["1.7"], ["760"], ["1076"], ["576"]],
            [["Aerotech 54mm Motor (J401FJ)"], ["2.8"], ["401"], ["912"], ["511"]],
            [["Aerotech 54mm Motor (J800T)"], ["1.6"], ["800"], ["1134"], ["595"]],
            [["Aerotech 38mm Motor (J825R)"], ["1.2"], ["825"], ["878"], ["497"]],
            [["Cesaroni 38mm Motor (J94)"], ["6.8"], ["94"], ["660"], ["372"]],
            [["Aerotech 38mm Motor (J425R)"], ["1.6"], ["425"], ["631"], ["364"]],
            [["Aerotech 38mm Motor (J500G)"], ["1.4"], ["500"], ["654"], ["375"]],
            [["Aerotech 38mm Motor (J420)"], ["1.6"], ["420"], ["635"], ["345"]],
            [["Aerotech 38mm Motor (J340M)"], ["1.8"], ["340"], ["577"], ["365"]]
            ]
kEngines = [
            [["Aerotech 54mm Motor (K456DM)"], ["2.9"], ["456"], ["1484"], ["866"]],
            [["Aerotech 54mm Motor (K2050ST)"], ["0.7"], ["2050"], ["2086"], ["1292"]],
            [["Cesaroni 54mm Motor (K300)"], ["8.4"], ["300"], ["2270"], ["1265"]],
            [["Cesaroni 54mm Motor (K260)"], ["8.7"], ["260"], ["2047"], ["1149"]],
            [["Cesaroni 54mm Motor (K1200)"], ["1.7"], ["1200"], ["1631"], ["960"]],
            [["Cesaroni 54mm Motor (K2045)"], ["0.7"], ["2045"], ["1290"], ["716"]],
            [["Cesaroni 54mm Motor (K940)"], ["1.8"], ["940"], ["1366"], ["768"]],
            [["Cesaroni 54mm Motor (K630)"], ["2.7"], ["630"], ["1410"], ["912"]]
            ]
def heightPrint():
    rEngine = input("Pick a class of engine a-l (lowercase):")
    rEngine= rEngine+("Engines")
    print("You have chosen class {}".format(rEngine))
    print("These are the engines in class {}".format(rEngine))
    for x in range 20:
        print(eval(rEngine[0][x]))

上面是 3D 数组的一部分，也是我要解决的问题。这可能是一种非常混乱的方式，但我希望能够在每个引擎之后使用 /n 从数组中打印引擎，但它不喜欢在 eval 行之后有方括号，也不喜欢在里面有一个 str方括号也是。

Answer 1

重要编辑：据我所知，使用 eval() 是不好的做法。如果您是唯一使用此工具的人，则以下解决方案很好，但如果其他人将访问此工具，则此方法很危险，因为输入 print(1)# 将使程序打印 1 并包含所有含义它。可以通过在接收到输入后检查输入字符是否在允许的输入范围内来修复代码

if rEngine not in ['k', 'j']:
    break # or do whatever action is needed, like prompting the user again

不过，解决此问题的“pythonic”方法是将名称映射到数组并以这种方式获取数组的字典

engines = {'jEngines': jEngines, 'kEngines': kEngines}
rEngine = engines[rEngine]

---

您可以在访问引擎之前eval() 引擎，然后将其作为数组访问

def heightPrint():
    rEngine = input("Pick a class of engine a-l (lowercase): ")
    rEngine = rEngine+"Engines"
    print("These are the engines in class {}".format(rEngine))
    print("You have chosen class {}".format(rEngine))
    rEngine = eval(rEngine)
    for x in rEngine:
        print(x[0][0])

我不确定你到底想打印什么，这个函数会给你命名为“Aerotech 54mm Motor (J1799N)”等等。

对于您帖子中的kEngines，该函数将产生以下输出：

heightPrint()

Pick a class of engine a-l (lowercase): k
You have chosen class kEngines
These are the engines in class kEngines
Aerotech 54mm Motor (K456DM)
Aerotech 54mm Motor (K2050ST)
Cesaroni 54mm Motor (K300)
Cesaroni 54mm Motor (K260)
Cesaroni 54mm Motor (K1200)
Cesaroni 54mm Motor (K2045)
Cesaroni 54mm Motor (K940)
Cesaroni 54mm Motor (K630)