我有一个这样的数据框：
POLY_KEY_I Class SP_Percent
FS01080100SM001 NA 5.0
MTGP 67.5
Meadow 25.0
Woodland 2.5
FS01080100SM002 PHP 85.0
SP 15.0
，如果POLY_KEY_I == Class和Meadow＆gt; = SP_Percent我想将20转换为MTGP，则每个uniqe WMTGP {1}}。
我想要的输出是：
POLY_KEY_I Class SP_Percent
FS01080100SM001 NA 5.0
WMTGP 67.5
Meadow 25.0
Woodland 2.5
FS01080100SM002 PHP 85.0
SP 15.0
我正在尝试的代码是：
df ['mask'] = ((df['Class'] == 'Meadow') & df['SP_Percent'] >=20)
mask = df.groupby(['POLY_KEY_I'])['mask'].transform('MTGP')
df.loc[mask,'Class']='WMTGP'
print(df)
但这会返回错误：
mask = final.groupby（['POLY_KEY_I']）['mask']。transform（'MTGP'）
文件“C：\ Users \ Stefano \ Anaconda2 \ lib \ site-packages \ pandas \ core \ groupby.py”，第2439行，转换 return self._transform_fast（lambda：getattr（self，func）（* args，** kwargs））
文件“C：\ Users \ Stefano \ Anaconda2 \ lib \ site-packages \ pandas \ core \ groupby.py”，第2484行，在_transform_fast中 values = func（）。values
文件“C：\ Users \ Stefano \ Anaconda2 \ lib \ site-packages \ pandas \ core \ groupby.py”，第2439行， return self._transform_fast（lambda：getattr（self，func）（* args，** kwargs））
文件“C：\ Users \ Stefano \ Anaconda2 \ lib \ site-packages \ pandas \ core \ groupby.py”，第520行， getattr （键入（自我）。名称，attr））
AttributeError：'SeriesGroupBy'对象没有属性'MTGP
编辑：
我不知道这是否有帮助，但如果我改变这一行：
mask = df.groupby(['POLY_KEY_I'])['mask'].transform('MTGP')
到此：
mask = df.groupby(['POLY_KEY_I'])['mask'].transform('any')
它会将相应POLY_KEY_ID的每个值更改为WMTGP，但我只想更改MTGP
答案 0 :(得分：2)
我使用groupby自定义函数apply完全将您的解决方案更改为f。对于检查字符串值，最好使用isin。
输入（添加第5行进行测试）：
POLY_KEY_I Class SP_Percent
0 FS01080100SM001 NaN 5.0
1 FS01080100SM001 MTGP 67.5
2 FS01080100SM001 Meadow 25.0
3 FS01080100SM001 Woodland 2.5
4 FS01080100SM002 PHP 85.0
5 FS01080100SM002 MTGP 85.0
6 FS01080100SM002 SP 15.0
def f(g):
if ((g['Class'].isin(['Meadow'])) & (g['SP_Percent'] >=20)).any():
g['Class'].loc[g['Class'].isin(['MTGP'])] = 'WMTGP'
return g
else:
return g
print df.groupby(['POLY_KEY_I']).apply(f)
POLY_KEY_I Class SP_Percent
0 FS01080100SM001 NaN 5.0
1 FS01080100SM001 WMTGP 67.5
2 FS01080100SM001 Meadow 25.0
3 FS01080100SM001 Woodland 2.5
4 FS01080100SM002 PHP 85.0
5 FS01080100SM002 MTGP 85.0
6 FS01080100SM002 SP 15.0
EDIT1：
添加时间：
%timeit df.groupby(['POLY_KEY_I']).apply(f)
100 loops, best of 3: 4.78 ms per loop
%timeit shahram(df)
10 loops, best of 3: 38.2 ms per loop
计时来源：
import pandas as pd
import numpy as np
import io
temp=u"""POLY_KEY_I;Class;SP_Percent
FS01080100SM001;NA;5.0
FS01080100SM001;MTGP;67.5
FS01080100SM001;Meadow;25.0
FS01080100SM001;Woodland;2.5
FS01080100SM002;PHP;85.0
FS01080100SM002;MTGP;85.0
FS01080100SM002;SP;15.0"""
df = pd.read_csv(io.StringIO(temp), sep=";", index_col=None, parse_dates=False)
print df
print df.dtypes
print df.index
def shahram(df):
df ['mask'] = ((df['Class'] == 'Meadow') & (df['SP_Percent'] >=20))
df2 = df[(df['mask']==True)][['POLY_KEY_I']]
df2['mask2']=True
df = pd.merge(df,df2,how='left')
df.ix[((df['mask2']==True) & (df['Class']=='MTGP')),'Class'] = 'WMTGP'
return df
def f(g):
if ((g['Class'].isin(['Meadow'])) & (g['SP_Percent'] >=20)).any():
g['Class'].loc[g['Class'].isin(['MTGP'])] = 'WMTGP'
return g
else:
return g
print df.groupby(['POLY_KEY_I']).apply(f)
print shahram(df)
答案 1 :(得分：1)
我是这样做的：
// FroggerComponent.java
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.io.*;
import javax.imageio.*;
public class FroggerComponent extends JComponent {
// Size of the game grid
public static final int WIDTH = 20;
public static final int HEIGHT = 7;
// Initial pixel size for each grid square
public static final int PIXELS = 50;
// Image filenames for car, lily, and frog
public static final String[] IMAGES = new String[] { "Images/frog.png", "Images/car.png", "Images/lily.png" };
// Colors for ROAD, WATER, and DIRT
public static final Color[] COLORS = new Color[] { Color.BLACK, Color.BLUE, Color.GRAY };
// Codes to store what is in each square in the grid
public static final int EMPTY = 0;
public static final int CAR = 1;
public static final int LILY = 2;
private Image frog;
private Image car;
private Image lily;
private int[][] grid = new int[WIDTH][HEIGHT];
Row[] rows = new Row[HEIGHT];
private int x;
private int y;
int x1 = 6;
int y1 = 10;
int dx;
private int dy;
private boolean dead;
/*
* Provided utility method to read in an Image object. If the image cannot
* load, prints error output and returns null. Uses Java standard
* ImageIO.read() method.
*/
private Image readImage(String filename) {
Image image = null;
try {
image = ImageIO.read(new File(filename));
} catch (IOException e) {
System.out.println("Failed to load image '" + filename + "'");
e.printStackTrace();
}
return (image);
}
private void readRow(String file) {
try {
FileReader fr = new FileReader(file);
BufferedReader br = new BufferedReader(fr);
String line = br.readLine();
int count = 1;
while ((line != null) && (line != "\n") && (line != "\r")) {
Row r = new Row(line);
rows[count] = r;
line = br.readLine();
count++;
}
} catch (IOException ex) {
System.out.println("File not found!");
}
}
public FroggerComponent(String filename) {
setPreferredSize(new Dimension(WIDTH * PIXELS, HEIGHT * PIXELS));
readRow(filename);
/*
* Add your code here ... readImage(...); ...
*/
frog = readImage("images/frog.png");
lily = readImage("Images/lily.png");
car = readImage("Images/car-red.png");
readRow("Images/world.txt");
reset();
}
public void reset() {
for (int x = 0; x < grid.length; x++)
for (int y = 0; y < grid[x].length; y++)
grid[x][y] = EMPTY;
dead = false;
x = 0;
y = 6;
repaint();
}
private void moveBy(int dx, int dy) {
if ((x1 + dx >= 0 && x + dx < WIDTH) && (y1 + dy >= 0 && y1 + dy < HEIGHT)) {
x1 += dx;
y1 += dy;
}
}
public boolean isWin() {
return (y == 0);
}
public void key(int code) throws ArrayIndexOutOfBoundsException {
/*
* Add your code here
*/
if (code == KeyEvent.VK_UP) {
x1 = x1 - 1;
} else if (code == KeyEvent.VK_DOWN) {
x1 = x1 + 1;
} else if (code == KeyEvent.VK_LEFT) {
y1 = y1 - 1;
} else if (code == KeyEvent.VK_RIGHT) {
y1 = y1 + 1;
}
this.repaint();
}
public void paintComponent(Graphics g) {
/*
* Add your code here
*
*
*/
// variables
int squareWidth = getWidth() / grid.length;
int squareHeight = getHeight() / grid[0].length;
// paints the rows
for (int y = 0; y < 20; y++) {
if (grid[y][x] == EMPTY) {
g.setColor(Color.GRAY);
g.fillRect(squareWidth * y, squareWidth * x, squareWidth, squareHeight);
}
}
x++;
for (int y = 0; y < 20; y++) {
if (grid[y][x] == EMPTY) {
g.setColor(Color.BLUE);
g.fillRect(squareWidth * y, squareWidth * x, squareWidth, squareHeight);
}
}
x++;
for (int y = 0; y < 20; y++) {
if (grid[y][x] == EMPTY) {
g.setColor(Color.BLACK);
g.fillRect(squareWidth * y, squareWidth * x, squareWidth, squareHeight);
}
}
x++;
for (int y = 0; y < 20; y++) {
if (grid[y][x] == EMPTY) {
g.setColor(Color.BLUE);
g.fillRect(squareWidth * y, squareWidth * x, squareWidth, squareHeight);
}
}
x++;
for (int y = 0; y < 20; y++) {
if (grid[y][x] == EMPTY) {
g.setColor(Color.BLUE);
g.fillRect(squareWidth * y, squareWidth * x, squareWidth, squareHeight);
}
}
x++;
for (int y = 0; y < 20; y++) {
if (grid[y][x] == EMPTY) {
g.setColor(Color.BLACK);
g.fillRect(squareWidth * y, squareWidth * x, squareWidth, squareHeight);
}
}
x++;
for (int y = 0; y < 20; y++) {
if (grid[y][x] == EMPTY) {
g.setColor(Color.GRAY);
g.fillRect(squareWidth * y, squareWidth * x, squareWidth, squareHeight);
}
}
// frog
g.drawImage(frog, squareWidth * y1, squareHeight * x1, squareWidth, squareHeight, this);
// lilypads
g.drawImage(lily, squareWidth, squareHeight, squareWidth, squareHeight, null);
g.drawImage(lily, squareWidth * 5, squareHeight, squareWidth, squareHeight, null);
g.drawImage(lily, squareWidth * 10, squareHeight, squareWidth, squareHeight, null);
g.drawImage(lily, squareWidth * 10, squareHeight * 3, squareWidth, squareHeight, null);
g.drawImage(lily, squareWidth * 8, squareHeight * 3, squareWidth, squareHeight, null);
g.drawImage(lily, squareWidth * 3, squareHeight * 3, squareWidth, squareHeight, null);
g.drawImage(lily, squareWidth * 2, squareHeight * 4, squareWidth, squareHeight, null);
g.drawImage(lily, squareWidth * 4, squareHeight * 4, squareWidth, squareHeight, null);
g.drawImage(lily, squareWidth * 12, squareHeight * 4, squareWidth, squareHeight, null);
g.drawImage(lily, squareWidth * 17, squareHeight * 4, squareWidth, squareHeight, null);
// cars
g.drawImage(car, squareWidth * 2, squareHeight * 5, squareWidth, squareHeight, null);
g.drawImage(car, squareWidth * 5, squareHeight * 5, squareWidth, squareHeight, null);
g.drawImage(car, squareWidth * 11, squareHeight * 5, squareWidth, squareHeight, null);
g.drawImage(car, squareWidth * 7, squareHeight * 2, squareWidth, squareHeight, null);
g.drawImage(car, squareWidth * 4, squareHeight * 2, squareWidth, squareHeight, null);
}
public void tick(int round) {
/*
* Add your code here
*/
}