Python trouble #1

[Cicada3301]

Excuse me for my ignorance, but I renamed the file with the mountains data to mountain3.txt,also changed the name of the file in the program but I am still getting :

 FileNotFoundError: [Errno 2] No such file or directory: 'mountain3.txt'

UPDATE: It's ok now with

 
with open ('mountain3.txt' ,'r',encoding = 'utf-8') as f :            
     for z in f:
       y =  z.split(',',maxsplit = 4)
       name = y[0]
       height = y[1]
       location = y[2]
       print(name,height,location)            

but the program doesn't do something

update No2

 
x = input('For which mountain do you want to learn ? :')
with open ('mountain3.txt' ,'r',encoding = 'utf-8') as f :            
     for z in f:
       y =  z.split(',',maxsplit = 4)
       name = y[0]
       height = y[1]
       location = y[2]
       b = list(name)
       c = list(height)
       d = list(location)
       for i in range(len(b)+1):
           if x in d:
              print(name[i],height[i],location[i])  #still does not do something