Question

我目前在python中遇到问题，我想做的是通过6个数组检查是否有负数，然后将一个加到相应的变量中。

我已经尝试了各种方法来解决此问题，但是没有真正的文档可以在网上找到对我有帮助的

BusA = ["-1","1","-1","1"]
BusB = ["-1","1","-1","1"]
BusC = ["-1","1","-1","1"]
BusD = ["-1","1","-1","1"]
BusE = ["-1","1","-1","1"]
BusF = ["-1","1","-1","1"]

Buses = "ABCDEF"

BusALate, BusBLate, BusCLate, BusDLate, BusELate, BusFLate = 0, 0, 0, 0, 0, 0

for c in Buses:
  Array = eval("Bus" + str(c))
  for i in Array:
    if(int(i) < 0):
      eval("Bus"+c+"Late") += 1

print(BusALate, BusBLate, BusCLate, BusDLate, BusELate, BusFLate)

如果可能的话，我只需要一种在if中格式化变量的方法，以便可以逐步将其更改为BusALate，BusBLate等...并在发现负数时添加。

Answer 1

根据Thierry Lathuille的建议，以下是使用词典如何简化代码的方法：

bus_schedules= {
    "A" : ["-1","1","-1","1"],
    "B" : ["-1","1","-1","1"],
    "C" : ["-1","1","-1","1"],
    "D" : ["-1","1","-1","1"],
    "E" : ["-1","1","-1","1"],
    "F" : ["-1","1","-1","1"]
}

bus_late = {"A" : 0, "B" : 0, "C" : 0, "D" : 0, "E" : 0, "F" : 0}

for (bus_name, bus_times) in bus_schedules.items():
    for i in bus_times :
        if (int(i) < 0):
            bus_late[bus_name]+=1

print(bus_late)

Answer 2

import numpy as np

buses =  np.array([[-1,1,-1,1],
                   [-1,1,-1,1],
                   [-1,1,-1,1],
                   [-1,1,-1,1],
                   [-1,1,-1,1],
                   [-1,1,-1,1]])

print(np.sum(buses<0, axis=1))

Answer 3

一步即可完成字符串转换和dict理解：

!TCMALLOC_LARGE_ALLOC_REPORT_THRESHOLD=21329330176 
!python3 "/content/gdrive/My Drive/my_folder/my_file.py"

这产生

busses = {'A':["-1","1","-1","1"],
          'B': ["-1","1","-1","1"],
          'C': ["-1","1","-1","1"],
          'D': ["-1","1","-1","1"],
          'E': ["-1","1","-1","1"],
          'F': ["-1","1","-1","1"]}

busses = {key: [(value + 1) if value < 0 else value
                for x in lst
                for value in [int(x)]]
          for key, lst in busses.items()}
print(busses)

如何在Python中格式化变量

3 个答案: