给出以下数据框:
State,City,Population,Poverty_Rate,Median_Age,
VA,XYZ,.,10.5%,42,
MD,ABC,"12,345",8.9%,.,
NY,.,987,654,.,41,
...
import pandas as pd
df = pd.read_csv("/path... /sample_data")
df.dtypes
返回
State Object
City Object
Population Object
Proverty_Rate Object
Median_Age Object
我尝试将适当的列的数据类型转换为int或float:
df = df.astype({"Population": int, "Proverty_rate": float, "Median_Age": int })
我收到
Value Error: invalid literal for int() with base 10: '12,345'
我怀疑逗号分隔符导致了此问题。如何从数据集中删除那些?
pd.read_csv(thousand=',')
中有一个参数,默认情况下将其设置为None。
data = """
State City Population Poverty_Rate Median_Age
VA XYZ 500,00 10.5% 42
MD ABC 12,345 8.9% .
NY . 987,654 . 41"""
from io import StringIO
import pandas as pd
df = pd.read_csv(StringIO(data),sep='\s+',thousands=',')
print(df)
State City Population Poverty_Rate Median_Age
0 VA XYZ 50000 10.5% 42
1 MD ABC 12345 8.9% .
2 NY . 987654 . 41
理想地,您需要做的是替换字符串标记,然后将字符串列强制转换为整数/浮点数。
#using your dict.
int_cols = ({"Population": int, "Poverty_Rate": float, "Median_Age": int })
for col in int_cols.keys():
df[col] = pd.to_numeric(df[col].astype(str).str.replace('%',''),errors='coerce')
print(df.dtypes)
State object
City object
Population int64
Poverty_Rate float64
Median_Age float64
dtype: object
print(df)
State City Population Poverty_Rate Median_Age
0 VA XYZ 50000 10.5 42.0
1 MD ABC 12345 8.9 NaN
2 NY . 987654 NaN 41.0
您可以尝试以下吗?首先将str.replace
列上,然后再将其转换为整数?
import pandas as pd
df = pd.DataFrame([
{'value': '123,445'},
{'value': '143,445,788'}
])
df['value'] = df['value'].str.replace(',', '').astype(int)