有人能告诉我IndexError在哪里吗？ （蟒蛇）

Question

我无法弄清楚代码中的IndexError在哪里，所以有人可以帮我解决

这是代码

def gap(g, m, n):
    def is_prime(n):
        for i in range(2, n):
            if n % i == 0:
                return False
        return True
    result = []
    r = []
    primes = [p for p in range(m, n) if is_prime(p)]
    for i in range(len(primes) - 1):
        if primes[i] - primes[i + 1] == g:
            r.append(primes[i - 1])
            r.append(primes[i])
    result.append(r[0])
    result.append(r[1])
    if result == []:
        return None
    else:
        return result
print (gap(2, 100, 110))

这是输出

Traceback (most recent call last):
  File "C:\Users\Harry\Documents\randompythonprograms\editable.py", line 20, in <module>
    print (gap(2, 100, 110))
  File "C:\Users\Harry\Documents\randompythonprograms\editable.py", line 14, in gap
    result.append(r[0])
IndexError: list index out of range

Answer 1

这是错误的原因。

r.append(primes[i - 1])

我需要i作为列表的第一个值id并传递（i - 1）。

Answer 2

#include "application.h"
SYSTEM_MODE(MANUAL);

// TCP setup
TCPServer server = TCPServer(23);
TCPClient client;

int range;
// char read;
String readString;
String sentRange;

// LIDAR sensor setup

const int monitorPin1 = 3;
const int monitorPin2 = 1;

const int triggerPin1 = 2;
const int triggerPin2 = 0;

long pulseWidth;

// Initialise averaging array
const int numberOfReadings = 10; // reasonable DOF from Measurement and Noise
const int med = numberOfReadings/2;
long readings[numberOfReadings];
int median;

void setup() {
    Serial.begin(9600);
    WiFi.clearCredentials();

    //LIDAR 
    pinMode(triggerPin1, OUTPUT); // Set pin 2 as trigger pin
    pinMode(D7, OUTPUT);
    digitalWrite(triggerPin1, LOW); // Set trigger HIGH for non-continuous read
    pinMode(monitorPin1, INPUT); // Set pin 3 as monitor pin

    pinMode(triggerPin2, OUTPUT); // Set pin 2 as trigger pin
    digitalWrite(triggerPin2, LOW); // Set trigger HIGH for non-continuous read
    pinMode(monitorPin2, INPUT); // Set pin 3 as monitor pin
    delay(2000);

    WiFi.on(); // if this isn't working, make sure it's set up for Photons (not Electrons!)
    WiFi.setCredentials("AndroidAP", "12345678"); // NB: must call WiFi.on() before this line. Not sure why.
    delay(2000);
    WiFi.connect();

    // start listening for clients
    server.begin();
}

int readLIDAR(int triggerPin, int monitorPin){
    pulseWidth = pulseIn(monitorPin, HIGH); // Count how long the pulse is high in microseconds
    pulseWidth = pulseWidth / 10; // 10usec = 1 cm of distance
    return pulseWidth;
}

long takeReading(int triggerPin, int monitorPin) {
  for (int i = 0; i < numberOfReadings; i++) {
    readings[i] = readLIDAR(triggerPin, monitorPin);
    delay(10); // There doesn't seem to be a requirement for a delay, but to be safe, delay = 10ms.
  }
  return *readings;
}

// Sort readings
long sort(long* readings) {
    // bubble sort with flag
    for (int i = 0; i < numberOfReadings; i++) {
        bool flag = true;
        for (int j = 1; j < numberOfReadings; j++) {
            if (readings[j-1] > readings[j]) {
                int t = readings[j-1];
                readings[j-1] = readings[j];
                readings[j] = t;
                flag = false;
            }
        }
        if (flag) break;
    }
    return *readings;
}

int range1(String command){
    if (command == "Get range 1\n") *readings = takeReading(triggerPin1, monitorPin1); // gather sufficient (typ: 10) readings
    else if (command == "Get range 2\n") *readings = takeReading(triggerPin2, monitorPin2); // gather sufficient (typ: 10) readings

    *readings = sort(readings); // sort in ascending order for median value
    median = (readings[med-1] + readings[med])/2; // get median value to send to app
    memset(readings, 0, sizeof(readings)); //clear previous readings

    return median;
}

String goGetCredentials() {
    WiFiAccessPoint ap[5];
    int found = WiFi.getCredentials(ap, 5);
    for (int i = 0; i < found; i++) {
        Serial.print("ssid: ");
        Serial.println(ap[i].ssid);
        // security is one of WLAN_SEC_UNSEC, WLAN_SEC_WEP, WLAN_SEC_WPA, WLAN_SEC_WPA2
        Serial.print("security: ");
        Serial.println(ap[i].security);
        // cipher is one of WLAN_CIPHER_AES, WLAN_CIPHER_TKIP
        Serial.print("cipher: ");
        Serial.println(ap[i].cipher);
    }
}

void loop() {

    if (client.connected()) {
        Serial.println("Client connected.");
        // read client for which sensor to query and send back result
        while (client.available()) {
            readString = "Get range 1\n";
            range = range1(readString);
            sentRange = "u" + String(range) + " cm" + "\n";
            Serial.print(sentRange);
            server.write(sentRange);

            delay(300);

            readString = "Get range 2\n";
            range = range1(readString);
            sentRange = "f" + String(range) + " cm" + "\n";
            Serial.print(sentRange);
            server.write(sentRange);
            delay(300);
        }
    } else {
        // if no client is yet connected, check for a new connection
        client = server.available();

        if(WiFi.hasCredentials()==true) {
          Serial.println("Has credentials.");
        //   goGetCredentials();
        } else {
          Serial.println("No credentials.");
        }

        Serial.println("Looking for server.");
        delay(2000);
    }
}

您已将r定义为空数组，并且在循环后仍为空数组。您可以通过添加简单的print语句来检查它。所以它是一个没有索引0或1的数组，所以它抛出了那个错误。