如何使用python在文件中查找特定范围？

我试图在文件中找到与特定MAC地址相等的特定范围

代码如下：

sensortag=0
while sensortag != "B4:99:4C:64:33:E0":
    os.system("hcitool lescan> scan.txt & pkill --signal SIGINT hcitool")
    scan = open("scan.txt", "r")
    readscan = scan.read()

    #read range 40-56 in file, NOTE: THIS WORKS IF I JUST KEEP IT if readscan[40] == "B", b being the start of the MAC address
    if readscan[40:56] == "B4:99:4C:64:33:E0":
        print "SensorTag found."
        sensortag = "B4:99:4C:64:33:E0"

代码只是无限循环

更新：多亏了jkalden，我的代码现在可以解决这个问题了：

if "B4:99:4C:64:33:E0" in readscan:
        print "SensorTag found."
        sensortag = "B4:99:4C:64:33:E0"

我使用for循环打印索引号和相应的值，以验证它是否是我需要的40-56范围

for index, i in enumerate(readscan):
    print index, i

---

问题是，当循环没有结束时，您正在进行。试试这样的

os.system("hcitool lescan> scan.txt & pkill --signal SIGINT hcitool")
found = False
with open('scan.txt') as fin:
    for line in fin:
        if line[40:56] == 'B4:99:4C:64:33:E0':
            found = True
            break

if found:
    print "SensorTag found."

---

我使用regexto查找所有macaddress

多亏了jkalden，我的代码现在可以使用以下解决方法：

if "B4:99:4C:64:33:E0" in readscan:
        print "SensorTag found."
        sensortag = "B4:99:4C:64:33:E0"

---

我在这里没有看到任何问题。我已经更新了标题：如何使用python在文件中查找特定范围？我不确定我是否正确，但是如果readscan:print“SensorTag found.”中的“B4:99:4C:64:33:E0”是如何的？？完美！如果readscan:print“SensorTag found”中的“B4:99:4C:64:33:E0”，SensorTag=“B4:99:4C:64:33:E0”有效！谢谢你，杰卡登@JonathanDavies检查代码这不起作用。如果为：if readscan[40]=“B”，则while循环结束。要查找的单个值，而不是范围[40:56]

if "B4:99:4C:64:33:E0" in readscan:
        print "SensorTag found."
        sensortag = "B4:99:4C:64:33:E0"