Error- local variable referenced before assignment-CodePudding

What I'm sure is another simple error, but I'm going around in circles. I'm trying to get it to show the first 10 lines in a csv using a function. I can get 1 line to show before it throws an error. Maybe my rows=0 needs to be moved down further, but I'm not sure and my attempts at moving it hasn't worked?


rows = 0

def lines():
    with open('iamacsvfile.csv') as file:
        dictreader = csv.DictReader(file)
        for row in dictreader:
            print(row)
            rows=rows 1
            if(rows>=10):
                break

lines()

UnboundLocalError Traceback (most recent call last) Input In [57], in <cell line: 14>() 11 if(rows>=5): 12 break ---> 14 lines()

Input In [57], in lines() 8 for row in dictreader: 9 print(row) ---> 10 rows=rows 1 11 if(rows>=5): 12 break

UnboundLocalError: local variable 'rows' referenced before assignment

CodePudding user response：

This should work:

def lines():
    rows = 0
    with open('iamacsvfile.csv') as file:
        dictreader = csv.DictReader(file)
        for row in dictreader:
            print(row)
            rows=rows 1
            if(rows>=10):
                break

lines()

CodePudding user response：

Your rows is outside the function so the lines function cannot access the variable. Try moving rows inside the lines function like this.

def lines():
    rows = 0

    with open('iamacsvfile.csv') as file:
        dictreader = csv.DictReader(file)
        for row in dictreader:
            print(row)
            rows=rows 1
            if(rows>=10):
                break

lines()

CodePudding user response：

You haven't defined rows.

But you don't need that, since csv.DictReader has line_num property, which increases with each iteration. It's better to use:

for row in dictreader:
    print(row)
    if dictreader.line_num >= 10:
        break