Python 合並字符串

題目：
a1=['A1','A2','B1','B2','C1','C2','C3','D1','D2']

a2=['A','B','C','D']

a1合並a2后得到這樣的列表['A1', 'A2', 'A', 'B1', 'B2', 'B', 'C1', 'C2', 'C3', 'C', 'D1', 'D2', 'D']

廢話不多說，直接上代碼

 

a1=['A1','A2','B1','B2','C1','C2','C3','D1','D2']

a2=['A','B','C','D']

start_place=0

for item in a2:
 for i in range(start_place,len(a1)):
 if i==len(a1)-1:
 a1.append(item)
 print("insert charater %s"%item)
 start_place=i+1
 else:
 str=a1[i]
 if str.startswith(item) is False:
 a1.insert(i,item)
 print("insert charater %s"%item)
 start_place = i + 1
 break
print(a1)