我试图循环处理多页格式相同的数据，以获得一个由所有数据拼接而成的大型主数据框。然而，当我运行这段代码时，master_df是空的，好像new_df没有被追加到主数据框中。有什么想法吗？先谢谢你
alphabet_list = ['a','b','c','d','e','f']
master_df = pd.DataFrame([])
for letter in alphabet_list:
player_df = pd.read_html('https://www.nfl.com/players/active/{}'.format(letter))
new_df = player_df[0]
master_df = new_df.append(new_df)
试试这个改动。
import pandas as pd
alphabet_list = ['a','b','c','d','e','f']
master_df = pd.DataFrame()
for letter in alphabet_list:
player_df = pd.read_html('https://www.nfl.com/players/active/{}'.format(letter))
master_df = master_df.append(player_df)
输出：
Player Current Team Position Status
0 Chidobe Awuzie Dallas Cowboys CB ACT
1 Josh Avery Seattle Seahawks DT ACT
2 Genard Avery Philadelphia Eagles OLB ACT
3 Anthony Averett Baltimore Ravens CB ACT
4 Lee Autry Chicago Bears DT ACT
5 Denico Autry Indianapolis Colts DT ACT
6 Tavon Austin Dallas Cowboys WR UFA
7 Blessuan Austin New York Jets DB ACT
8 Antony Auclair Tampa Bay Buccaneers TE ACT
9 Jeremiah Attaochu Denver Broncos LB ACT
10 Hunter Atkinson Atlanta Falcons OT ACT
11 John Atkins Detroit Lions DE ACT
12 Geno Atkins Cincinnati Bengals DT ACT
13 Marcell Ateman Las Vegas Raiders WR ACT
14 George Aston New York Giants RB ACT
15 Dravon Askew-Henry New York Giants DB ACT
16 Devin Asiasi New England Patriots TE ACT
17 George Asafo-Adjei New York Giants OT ACT
18 Ade Aruna Las Vegas Raiders DE ACT
19 Grayland Arnold Philadelphia Eagles SAF ACT
20 Dan Arnold Arizona Cardinals TE ACT
21 Damon Arnette Las Vegas Raiders CB UDF
22 Ray-Ray Armstrong Dallas Cowboys LB UFA
23 Ka'John Armstrong Denver Broncos OT ACT
24 Dorance Armstrong Dallas Cowboys DE ACT
25 Cornell Armstrong Houston Texans DB ACT
26 Terron Armstead New Orleans Saints OT ACT
27 Ryquell Armstead Jacksonville Jaguars RB ACT
28 Arik Armstead San Francisco 49ers DE ACT
29 Alex Armah Carolina Panthers FB ACT
.. ... ... ... ...
70 Mark Fields Minnesota Vikings CB ACT
71 Sam Ficken New York Jets K ACT
72 Jason Ferris Carolina Panthers LB ACT
73 Clelin Ferrell Las Vegas Raiders DE ACT
74 Reid Ferguson Buffalo Bills LS ACT
75 Josh Ferguson Washington Redskins RB ACT
76 Jaylon Ferguson Baltimore Ravens LB ACT
77 Blake Ferguson Miami Dolphins LS ACT
78 James Ferentz New England Patriots C UFA
79 Rashad Fenton Kansas City Chiefs DB ACT
80 Darren Fells Houston Texans TE UFA
81 Jon Feliciano Buffalo Bills OG ACT
82 Clayton Fejedelem Miami Dolphins DB ACT
83 Matt Feiler Pittsburgh Steelers OT RFA
84 Jordan Fehr Minnesota Vikings LB ACT
85 Breiden Fehoko Los Angeles Chargers DT ACT
86 Dan Feeney Los Angeles Chargers OG ACT
87 Tavien Feaster Jacksonville Jaguars RB ACT
88 Foley Fatukasi New York Jets DT ACT
89 Rojesterman Farris Atlanta Falcons DB ACT
90 Wesley Farnsworth Denver Broncos LS ACT
91 Matthias Farley New York Jets DB ACT
92 Noah Fant Denver Broncos TE ACT
93 George Fant New York Jets OT ACT
94 David Fales New York Jets QB ACT
95 Nico Falah Denver Broncos C ACT
96 Ka'imi Fairbairn Houston Texans K ACT
97 Jovahn Fair Kansas City Chiefs OG ACT
98 Brandon Facyson Los Angeles Chargers DB ACT
99 Kyler Fackrell New York Giants LB ACT
[571 rows x 4 columns]