Python附加到.txt

Question

Hi im still learning python and currently trying to write some data to a txt file. I'm having issues with adding more than 1 persons details.I can the first persons details and it works fine but when I choose to add another persons set of details I get the following error.

line 58, in <module>
    datalist.append(first)
AttributeError: 'map' object has no attribute 'append'

any help would be appreciated, I did check other similar questions but couldn't work it out.

genderlist=["M", "F",]
moredata="Y"

datalist=[]
while (moredata=="Y" or moredata== "y"):

    datafile = open ("peSchool.text", "a+")
    first=input( "enter first name ")
    while not first.isalpha():
        print (" name should be alphabetic")
        first=input("enter first name ")
    second=input("surname ")
    while not second.isalpha():
        print (" surname should be alphabetic")
        second=input("enter surname ")
    postcode=input("postcode ")
    gender=input("enter gender ")
    gender=gender.upper()
    while gender not in genderlist:
        print ("gender should be M, F ")
        gender = input("Gender ")
        gender = gender.upper() 
    age=input("enter age ")
    while int(age) not in range(11,15):
        print(" age must be betwwen 11 and 15 ")
        age=input("enter age ")
    if int(age) ==11:
        group="1"
    elif int(age) ==12:
        group="2"
    elif int(age) ==13:
        group="3"
    else:
        group="4"


    unit=int(input("enter SATS units"))
    while int(unit) not in range(4,9):
        print(" SATS must be between 4 - 8 ")
        unit=input("enter SATS units")
    if int(unit) ==4:
        if gender=="M":
            unit = "Blake House"
        elif gender=="F":
            unit = "Woolfe House"
    elif int(unit) in range (5,6):
        if gender=="M":
            unit = "Harrison House"
        elif gender=="F":
            unit = "Gordon House"
    else:
        unit = "Jackson House"

    datalist.append(first)
    datalist.append(second)
    datalist.append(postcode)
    datalist.append(gender)
    datalist.append(age)
    datalist.append(unit)

    print (datalist.count)
    datalist = map(str, datalist)
    line = ",".join(datalist)
    datafile.writelines(line + "\n")





    print("First Name", first, "Surname", second, "Postcode", postcode, "Gender", gender, "Age", age, "house", unit, "Science Group ", group,)
    datafile.close()
    moredata=input("more students y/n ")
    moredata = moredata.upper()

Answer 1

There are a few things wrong here.

As Patrick Haugh points out above, map() returns a map, not a list, and so doesn't have an .append() method. You can solve this by converting the map object in a list as he mentions: datalist = list(map(str, datalist))

There is also the fact that the Python lists don't have a .count attribute. Instead, you presumably want to know the length of the list, so you can just do print(len(datalist)) .

Finally, there is a logical error: you will either need to write ONE line for each student at the end of the outer while loop, or else collect all the collected students and write them out at once. The former is much simpler. Just move the clearing of the datalist variable, inside the loop, to the top, rather than before it. Also note that since you are normalizing case with moredata = moredata.upper() and the bottom of the loop, you don't need to check for both cases at the top.

while (moredata=="Y"):
    datalist=[]
...