Iterate through list and append new rows to dataframe-CodePudding

I have a list of strings that I want to perform operations on and append to rows in a dataframe. Running these operations on a single string works fine but I am having trouble looping through. The code below returns an empty dataframe and I am not sure why?

col_names = ["Version Available", "Newer Version Available"]

def my_function(item):
  for x in item:
    querywords = x.split()
    resultwords = [word for word in querywords if word not in stopwords]
    result = ' '.join(resultwords)
    line = re.findall(r'\bNewer.*(?=\sVersion\b)', result)
    line = "".join(line)
    line = line.replace("Newer Version Available :", "")
    line2 = re.findall(r'(Version.*){2}(?=\sSource\b)', result)
    line2 = "".join(line2)
    line2 = line2.replace("Version Available :", "")
    s = [[line]   [line2]]
    data = pd.DataFrame(s)
    data.columns = col_names

df = my_function(my_list)

CodePudding user response：

You are creating the data frame inside the for loop, which means that with each loop, you are re-creating the data frame. Moving it outside the for loop should help.

CodePudding user response：

Is this something you are looking for?


col_names = ["Version Available", "Newer Version Available"]

def my_function(item):
    df = pd.DataFrame(columns=col_names) #initialize data frame
    for x in item:
        querywords = x.split()
        resultwords = [word for word in querywords if word not in stopwords]
        result = ' '.join(resultwords)
        line = re.findall(r'\bNewer.*(?=\sVersion\b)', result)
        line = "".join(line)
        line = line.replace("Newer Version Available :", "")
        line2 = re.findall(r'(Version.*){2}(?=\sSource\b)', result)
        line2 = "".join(line2)
        line2 = line2.replace("Version Available :", "")
        df.loc[len(df.index)] = [line,line2] # add row to data
    return df

df = my_function(my_list)

Reference

Add new row to Panda data frame