1. x ,series는 colmn을 나타낸다
2. x, b로 끝나는 열 이름을 의미함
3. x ,데이터 프레임 형식으로 출력됨
4. x ,리스트를 먼저 dataframe으로 변 환해야 함

import pandas as pd
import numpy as np
#1번
student_dict_list = [{'이름': 'Jake', '키': 175, '성적': 'A'}, {'이름': 'Jay', '키': 183, '성적': 'B'}]

df = pd.DataFrame(student_dict_list)

def add_cm(height_array):
return np.char.add(height_array.astype(str), 'cm')

df['키'] = add_cm(df['키'].values)
print(df)

#2번
students = [
{ "name" : "johanson", "age" : 23, "grade" : "B"},
{ "name" : "kelvin", "age" : 21, "grade" : "A"},
{ "name" : "smith", "age" : 22, "grade" : "F"},
{ "name" : "Jin", "age" : 20, "grade" : "A"},
{ "name" : "Chalie", "age" : 22, "grade" : "C"},
{ "name" : "Jackson", "age" : 21, "grade" : "B"},
{ "name" : "Michelle", "age" : 21, "grade" : "A"},
{ "name" : "Lisa", "age" : 24, "grade" : "F"}
]

df = pd.DataFrame(students)

grouped = df.groupby('grade')

for grade, group in grouped:
print(f"{grade} : {len(group)}")
print(group, "\\n")

#3번
data = {
"Fruit": ["Apple", "Banana", "Cherry"],
"Amount": [3, 2, 10],
"Price": [3000, 1500, 7000]
}

df = pd.DataFrame(data)

print(df)

#4번

df1 = pd.read_csv('pl_records.txt', delimiter='  ')
df2 = pd.read_csv('laliga_records.txt', delimiter='  ')

df_combined = pd.concat([df1, df2], ignore_index=True)

df_combined['Attack_pts'] = df_combined['Goals'] + df_combined['Assists']

def rate(attack_pts):
if attack_pts >= 9:
return "Incredible"
elif attack_pts >= 6:
return "Great"
else:
return "Good"

df_combined['Rating'] = df_combined['Attack_pts'].apply(rate)

df_combined.to_csv('player_stats.csv', index=False)

print(df_combined)