Trying to add content to an existing dataFrame - python-3.x

Question

I've been trying for days to find a solution to my problem. I am trying to add content to a pre-existing column in a data frame, however when I print the screen my program shows me that only the first 100 lines are being modified, it is never shown beyond line 100 and the items are not added but overwritten. I've tried several ways and it always gives an error, the closest way to what I want is this print that I put in the post. Could someone help me, I would be very grateful.
import functions
import pandas as pd
from time import sleep
from selenium import webdriver
from selenium.webdriver.firefox.options import Options
pd.set_option('max_rows', 10)
# Module of which the page link returns
site = functions.pagina()
#Browser Options
options = Options()
options.headless = True # Prevent browser from opening
driver = webdriver.Firefox(options=options) #Include options in browser
#Run browser with URL
driver.get(site)
# Wait in seconds for the page to load
print('Esperando 5s')
sleep(5)
#Create Data Frame
df = pd.DataFrame(columns = ['rank','nome','classe','item_lvl','servidor','mortes_temporada'], index=None)
while True:
#Get the 'next page' variable
next_page = driver.find_element_by_css_selector('#pagination-hook > nav > ul > li:nth-child(2) > a')
#As long as the Next variable is empty
if next_page is not None:
#Url of current page
driver.get(driver.current_url)
print(driver.current_url[-6:].upper())
#Attempting to insert data into existing rank column
ranks = pd.Series([rank_page.text for rank_page in driver.find_elements_by_xpath('//div[4]//div[1]/table/tbody/tr/td[1]')])
#MY PROBLEM ADDING CONTENT TO A COLUMN
df['rank'] =+ ranks
#Click on Next
driver.execute_script("arguments[0].click();", next_page)
sleep(4)
else:
break
print('*' * 80)
print(df)
print('*' * 80)
RETURN PRINT - IMAGE
Esperando 5s
PAGE=1
********************************************************************************
rank nome classe item_lvl servidor mortes_temporada
0 1 NaN NaN NaN NaN NaN
1 2 NaN NaN NaN NaN NaN
2 3 NaN NaN NaN NaN NaN
3 4 NaN NaN NaN NaN NaN
4 5 NaN NaN NaN NaN NaN
.. ... ... ... ... ... ...
95 96 NaN NaN NaN NaN NaN
96 97 NaN NaN NaN NaN NaN
97 98 NaN NaN NaN NaN NaN
98 99 NaN NaN NaN NaN NaN
99 100 NaN NaN NaN NaN NaN
[100 rows x 6 columns]
********************************************************************************
PAGE=2
********************************************************************************
rank nome classe item_lvl servidor mortes_temporada
0 101 NaN NaN NaN NaN NaN
1 102 NaN NaN NaN NaN NaN
2 103 NaN NaN NaN NaN NaN
3 104 NaN NaN NaN NaN NaN
4 105 NaN NaN NaN NaN NaN
.. ... ... ... ... ... ...
95 196 NaN NaN NaN NaN NaN
96 197 NaN NaN NaN NaN NaN
97 198 NaN NaN NaN NaN NaN
98 199 NaN NaN NaN NaN NaN
99 200 NaN NaN NaN NaN NaN
[100 rows x 6 columns]
********************************************************************************

Answer 1

When you add data to a column in Pandas, and df is a DataFrame, you have to include data for the rest of the columns for every row.
In your case, the fix is:
df2 = pd.DataFrame({
"rank": [rank_page.text for rank_page in driver.find_elements_by_xpath('//div[4]//div[1]/table/tbody/tr/td[1]')],
"nome": np.nan,
"classe": np.nan,
"item_lvl": np.nan,
"servidor": np.nan,
"mortes_temporada": np.nan
})
df = df.append(df2)