C# code:

using System;
using System.IO;
using System.Security.Cryptography;
using System.Text;

namespace LamicSdk.Func
{
    public class HelpEncrypt
    {
        private static string GetDefaultKeyAndIv()
        {
            return "";
        }



        /// <summary>字符串DES加密函数</summary>
        /// <param name="str">被加密字符串</param>
        /// <param name="keyAndIv">加密向量和密钥</param>
        /// <returns>加密后字符串</returns>
        public static string Encode(string str, string keyAndIv = null)
        {
            try
            {
                keyAndIv = string.IsNullOrEmpty(keyAndIv) ? GetDefaultKeyAndIv() : keyAndIv;
                var provider = new DESCryptoServiceProvider
                {
                    Key = Encoding.ASCII.GetBytes(keyAndIv),
                    IV = Encoding.ASCII.GetBytes(keyAndIv)
                };
                var bytes = Encoding.UTF8.GetBytes(str);
                using (var memoryStream = new MemoryStream())
                {
                    using (var cryptoStream = new CryptoStream(memoryStream, provider.CreateEncryptor(), CryptoStreamMode.Write))
                    {
                        cryptoStream.Write(bytes, 0, bytes.Length);
                        cryptoStream.FlushFinalBlock();
                        var builder = new StringBuilder();
                        foreach (var num in memoryStream.ToArray())
                        {
                            builder.AppendFormat("{0:X2}", num);
                        }
                        return builder.ToString();
                    }          
                }
            }
            catch (Exception)
            {
                return null;
            }
        }



        /// <summary><![CDATA[字符串DES解密函数]]></summary>
        /// <param name="str"><![CDATA[被解密字符串 ]]></param>
        /// <param name="keyAndIv">解密向量和密钥</param>
        /// <returns><![CDATA[解密后字符串]]></returns>
        public static string Decode(string str, string keyAndIv = null)
        {
            try
            {
                keyAndIv = string.IsNullOrEmpty(keyAndIv) ? GetDefaultKeyAndIv() : keyAndIv;

                var provider = new DESCryptoServiceProvider
                {
                    Key = Encoding.ASCII.GetBytes(keyAndIv),
                    IV = Encoding.ASCII.GetBytes(keyAndIv)
                };
                var buffer = new byte[str.Length / 2];
                for (var i = 0; i < str.Length / 2; i++)
                {
                    var num2 = Convert.ToInt32(str.Substring(i * 2, 2), 0x10);
                    buffer[i] = (byte)num2;
                }
                using (var memoryStream = new MemoryStream())
                {
                    using (var cryptoStream =new CryptoStream(memoryStream, provider.CreateDecryptor(), CryptoStreamMode.Write))
                    {
                        cryptoStream.Write(buffer, 0, buffer.Length);
                        cryptoStream.FlushFinalBlock();
                        return Encoding.UTF8.GetString(memoryStream.ToArray());
                    }
                }
            }
            catch (Exception)
            {
                return null;
            }
        }
    }
}


python code:

import pyDes
import binascii