我正在抓取一個 wiki 頁面，但<td>某些行中有一些空元素，因此我使用了：
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())
將這些行元素存盤在串列中，但是當我列印row_list.
那些rows_list有空<td>值的，現在應該有'NA'附加值，那些仍然是空的，即'NA' have not appended in list.
我怎么能解決這個問題？
uj5u.com熱心網友回復：
注意 問題需要改進 - 雖然你在這里更新只有兩個選項來解決
選項1
使用 Pandas 以快速且恰當的方式獲取表格：
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])
選項#2
將串列放在回圈之前，這樣您就可以避免覆寫并檢查縮進：
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())
uj5u.com熱心網友回復：
這里有幾件事：
- 不要
list用作變數。這是python中的預定義方法。 - 該
td.text不是None。實際上有一個字串作為內容（即：' '） - 您沒有遍歷 tr 標簽和 td 標簽（或至少在您在此處提供的代碼中）。您需要創建 tr 標簽串列和要在 for 回圈中使用的 td 元素。
試試這個：
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())
輸出：
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.']
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