如何摆脱事件和日期周围的方括号？

Question

calendar = []
while True:
    choice = input ("enter a,b,c,d or e")
    if choice == "e":
        print ("you have quitted this program")
        break #to quit the entire program
    if choice == "a":
        newevent = input ("enter the name of an event you want to add")
        y= int(input("enter the year of your event"))
        m = int(input("enter the month of your event"))
        d = int(input("enter the day of your event"))
        h = int(input("enter the hour of your event"))
        mi = int(input("enter the minute of your event"))
        calendar.append ([newevent,y,m,d,h,mi])
        print (calendar)
        f = open("calendar.txt","w")
        f.write (str(calendar)+"\n")
        f.close()



f = open('calendar.txt','r')
st = f.readlines()
print (st)

for i in range (0,len(st)):
    st[i] = st[i].strip("\n")
    print (st)
    f.close()

This is my output:

[['swim', 2020, 4, 2, 3, 2]]
["[['swim', 2020, 4, 2, 3, 2]]\n"]
["[['swim', 2020, 4, 2, 3, 2]]"]

I want to get rid of the square brackets around my code to make it swim,2020,4,2,3,2. Do I have to open the file before while True ?

Answer 1

For just stripping the end characters, use:

"[1, 2, 3]"[1:-1]

which will do just that. Strip the first character from left and right. But in case you want to save text or anything else, it'll require more work on your side to handle such special cases.

When saving you call f.write (str(calendar)+"\n") which if encounters a list does this:

[1, 2, 3]
    |
    v
"[1, 2, 3]"

if you want to convert back into Python list, simply use ast.literal_eval() on that via:

from ast import literal_eval
mylist = literal_eval("[1, 2, 3]")
print(type(mylist))
print(mylist[0])

Or instead of plain str(object) use a better structure when saving to a file such as json .

Answer 2

Use this code

import json

calendar = []
while True:
    choice = input ("enter a,b,c,d or e : ")
    if choice == "e":
        print ("you have quitted this program")
        break #to quit the entire program
    if choice == "a":
        newevent = input ("enter the name of an event you want to add : ")
        y= int(input("enter the year of your event : "))
        m = int(input("enter the month of your event : "))
        d = int(input("enter the day of your event : "))
        h = int(input("enter the hour of your event : "))
        mi = int(input("enter the minute of your event : "))
        data = [newevent,y,m,d,h,mi]
        calendar.append(data)

with open("calendar.json","w") as f:
    f.write(f"{json.dumps(calendar)}")

with open('calendar.json','r') as f:
    st = f.read()
    j_data = json.loads(st)

    print(j_data)

Answer 3

Hy, since you want to remove the long brackets of the array. You can use the strip function.And remember to convert your array to a string if not aready For example:

str1="['a','b']"
str1=str1.strip('[]')
print(str1)

This will give a string 'a','b'.Hope this helps you