python查找文件中某個字符串出現的次數

'''查找文件中某個字符串總共出現的次數'''
def findStr(str):
    with open("filePath",'r') as f:
        counts = 0
        for line in f.readlines():
            time = line.count(str)
            counts += time
        print("%s出現的次數：%d"%(str,counts))

findStr("str")