I am scraping a wiki page, but there are some empty <td> elements in some rows, therefore I used :

for tr in table1.tbody:
list = []
for td in tr:
    try:
        if(td.text is None): list.append('NA')
        else: list.append(td.text.strip())
        
    except:
        list.append(td.strip())

to store those rows element in a list, but when I print row_list.

Those rows_list with empty <td> value, which should now have append 'NA' value, those are still empty, i.e, 'NA' have not appended in list.

How could I fix this?

CodePudding user response：

Note Question needs improvment - While you update here just two option to fix

Option#1

Use pandas to get the tables in a quick and propper way:

import pandas as pd
pd.concat(pd.read_html('https://en.wikipedia.org/wiki/List_of_Falcon_9_and_Falcon_Heavy_launches#Past_launches')[2:11])

Option #2

Put the list outside before your loops, so you avoid overwriting and check your indentation:

data = []
for tr in table1.tbody:

    for td in tr:
        try:
            if(td.text is None): data.append('NA')
            else: data.append(td.text.strip())
        
        except:

        data.append(td.strip())

CodePudding user response：

Few things here:

1. don't use list as a variable. It's a predefined method in python.
2. the td.text is not None. There is actually an string as content (Ie: ' ')
3. You are not iterating through the tr tags and td tags (or atleast in the code you are providing here). You need to create your list of tr tags, and td elements to use in your for loop.

Try this:

import requests
from bs4 import BeautifulSoup

url = 'https://en.wikipedia.org/wiki/List_of_Falcon_9_and_Falcon_Heavy_launches#Past_launches'

response = requests.get(url)
soup = BeautifulSoup(response.text, 'html.parser')
table1 = soup.find_all('table')[2]


stored_list = []
for tr in table1.tbody.find_all('tr'):
    for td in tr.find_all('td'):
        if td.text.strip() == '': 
            stored_list.append('NA')
        else: 
            stored_list.append(td.text.strip())

Output:

print(stored_list)
['4 June 2010,18:45', 'F9 v1.0[7]B0003[8]', 'CCAFS,SLC-40', 'Dragon Spacecraft Qualification Unit', 'NA', 'LEO', 'SpaceX', 'Success', 'Failure[9][10](parachute)', 'First flight of Falcon 9 v1.0.[11] Used a boilerplate version of Dragon capsule which was not designed to separate from the second stage.(more details below) Attempted to recover the first stage by parachuting it into the ocean, but it burned up on reentry, before the parachutes even go to deploy.[12]', '8 December 2010,15:43[13]', 'F9 v1.0[7]B0004[8]', 'CCAFS,SLC-40', 'Dragon demo flight C1(Dragon C101)', 'NA', 'LEO (ISS)', 'NASA (COTS)\nNRO', 'Success[9]', 'Failure[9][14](parachute)', "Maiden flight of SpaceX's Dragon capsule, consisting of over 3 hours of testing thruster maneuvering and then reentry.[15] Attempted to recover the first stage by parachuting it into the ocean, but it disintegrated upon reentry, again before the parachutes were deployed.[12] (more details below) It also included two CubeSats,[16] and a wheel of Brouère cheese. Before the launch, SpaceX discovered that there was a crack in the nozzle of the 2nd stage's Merlin vacuum engine. So Elon just had them cut off the end of the nozzle with a pair of shears and launched the rocket a few days later. After SpaceX had trimmed the nozzle, NASA was notified of the change and they agreed to it.[17]", '22 May 2012,07:44[18]', 'F9 v1.0[7]B0005[8]', 'CCAFS,SLC-40', 'Dragon demo flight C2 [19](Dragon C102)', '525\xa0kg (1,157\xa0lb)[20] (excl. Dragon mass)', 'LEO (ISS)', 'NASA (COTS)', 'Success[21]', 'No attempt', 'The Dragon spacecraft demonstrated a series of tests before it was allowed to approach the International Space Station. Two days later, it became the first commercial spacecraft to board the ISS.[18] (more details below)', '8 October 2012,00:35[22]', 'F9 v1.0[7]B0006[8]', 'CCAFS,SLC-40', 'SpaceX CRS-1[23](Dragon C103)', '4,700\xa0kg (10,400\xa0lb) (excl. Dragon mass)', 'LEO (ISS)', 'NASA (CRS)', 'Success', 'No attempt', 'Orbcomm-OG2[24]', '172\xa0kg (379\xa0lb)[25]', 'LEO', 'Orbcomm', 'Partial failure[26]', "CRS-1 was successful, but the secondary payload was inserted into an abnormally low orbit and subsequently lost. This was due to one of the nine Merlin engines shutting down during the launch, and NASA declining a second reignition, as per ISS visiting vehicle safety rules, the primary payload owner is contractually allowed to decline a second reignition. NASA stated that this was because SpaceX could not guarantee a high enough likelihood of the second stage completing the second burn successfully which was required to avoid any risk of secondary payload's collision with the ISS.[27][28][29]", '1 March 2013,15:10', 'F9 v1.0[7]B0007[8]', 'CCAFS,SLC-40', 'SpaceX CRS-2[23](Dragon C104)', '4,877\xa0kg (10,752\xa0lb) (excl. Dragon mass)', 'LEO (ISS)', 'NASA (CRS)', 'Success', 'No attempt', 'Last launch of the original Falcon 9 v1.0 launch vehicle, first use of the unpressurized trunk section of Dragon.[30]', '29 September 2013,16:00[31]', 'F9 v1.1[7]B1003[8]', 'VAFB,SLC-4E', 'CASSIOPE[23][32]', '500\xa0kg (1,100\xa0lb)', 'Polar orbit LEO', 'MDA', 'Success[31]', 'Uncontrolled(ocean)[d]', 'First commercial mission with a private customer, first launch from Vandenberg, and demonstration flight of Falcon 9 v1.1 with an improved 13-tonne to LEO capacity.[30] After separation from the second stage carrying Canadian commercial and scientific satellites, the first stage booster performed a controlled reentry,[33] and an ocean touchdown test for the first time. This provided good test data, even though the booster started rolling as it neared the ocean, leading to the shutdown of the central engine as the roll depleted it of fuel, resulting in a hard impact with the ocean.[31] This was the first known attempt of a rocket engine being lit to perform a supersonic retro propulsion, and allowed SpaceX to enter a public-private partnership with NASA and its Mars entry, descent, and landing technologies research projects.[34] (more details below)', '3 December 2013,22:41[35]', 'F9 v1.1B1004', 'CCAFS,SLC-40', 'SES-8[23][36][37]', '3,170\xa0kg (6,990\xa0lb)', 'GTO', 'SES', 'Success[38]', 'No attempt[39]', 'First Geostationary transfer orbit (GTO) launch for Falcon 9,[36] and first successful reignition of the second stage.[40] SES-8 was inserted into a Super-Synchronous Transfer Orbit of 79,341\xa0km (49,300\xa0mi) in apogee with an inclination of 20.55° to the equator.']