在python中出现搜索项的打印行

Question

I'm trying to get my program to print the line in which a search item occurs in Python. This is my current attempt:

search = input("Input your search term: ")  
found = 0
printline == False

with open ("search.txt", 'r') as data:
    for line in data: 
        if search.casefold() in line.casefold():
            found += line.casefold().count(search.casefold())  #adds the number of occurences within a line
            printline == True
        if printline == True:
            print(line)
        else: 
            printline == False

print("{} occurence(s) of the search item was/were found".format(found))

It keeps saying "printline" not defined. I thought I defined it at the top.

Update: I removed "printline" as global variable and moved it to the beginning of a for loop. Now the code prints every line of text (not just the lines that contain the search term). This is what I was trying to avoid and the reason I came up with the "printline" variable to begin with.

To clarify, I have tried:

search = input("Input your search term: ")
found = 0


with open ("search.txt", 'r') as data:
    for line in data:
        if search.casefold() in line.casefold():
            found += line.casefold().count(search.casefold())  #adds the number of occurences within a line
            print(line)

print("{} occurence(s) of the search item was/were found".format(found)) 

and I have tried:

search = input("Input your search term: ")
found = 0


with open ("search.txt", 'r') as data:
    for line in data:
        printline = False
        if search.casefold() in line.casefold():
            found += line.casefold().count(search.casefold())  #adds the number of occurences within a line
            printline = True
        if printline == True:
            print(line)
        else:
            printline = False

print("{} occurence(s) of the search item was/were found".format(found))

and both methods end up spitting out every line of the text file. Any ideas? Thanks for everyone's help so far.

Answer 1

You're using an equivalence marker (==) to set your printline variable.

It should be "printline = False" to set, "printline == False" to compare

Try this:

search = input("Input your search term: ")
found = 0
printline = False

with open ("search.txt", 'r') as data:
    for line in data:
        if search.casefold() in line.casefold():
            found += line.casefold().count(search.casefold())  #adds the number of occurences within a line
            printline = True
        if printline == True:
            print(line)
        else:
            printline = False

print("{} occurence(s) of the search item was/were found".format(found))

EDIT: We should be able to remove the need for the printline variable.

search = input("Input your search term: ")
found = 0

with open ("search.txt", 'r') as data:
    for line in data:
        if search.casefold() in line.casefold():
            found += line.casefold().count(search.casefold())  #adds the number of occurences within a line
            print(line) # This should only trigger if your if search.casefold() is in the line.casefold()

print("{} occurence(s) of the search item was/were found".format(found))