Error while writing a file

Question

I am trying to write a file but i am getting the following error: TypeError: a bytes-like object is required, not 'str'

import requests, pandas
from bs4 import BeautifulSoup

r = requests.get("https://www.basketball-reference.com/players/a/")
c = r.content
soup = BeautifulSoup(c, "html.parser")
full_record_heading = soup.findAll("tr")
full_record = soup.findAll("tr")
playerdata = ""
playerdata_saved = ""
for record in full_record:
    playerdata = ""
    for player in record.findAll("td"):
        playerdata = playerdata +","+player.text
    playerdata_saved = playerdata_saved + playerdata[1:]+("\n")
# print(playerdata_saved)

header="From,To,Pos,Ht,Wt,Birth Date,College"
file=open("Basketball.csv","r+b")
file.write(header)

Can anyone tell me the reason for the error? How can we know the correct syntax of any command and documentation available? I am new to python

Answer 1

When you open a file in python, you must specify its "file mode" - read-only, write-only, read AND write, and if the file is binary. So, in this line:

open("Basketball.csv","r+b")

You opened your file as READ-ONLY, and set the file to be read as BINARY. You should have opened the file as:

open("Basketball.csv","w")

As write and as STRING

Nevertheless, you are manually writting a CSV file - you do not have to do that in Pyhton! Look at this example:

import requests
import pandas  # Always import in different lines
from bs4 import BeautifulSoup

r = requests.get("https://www.basketball-reference.com/players/a/")
c = r.content
soup = BeautifulSoup(c, "html.parser")
full_record_heading = soup.findAll("tr")
full_record = soup.findAll("tr")

# Initialize your data buffer
my_data = []

# For each observation in your data source
for record in full_record:
    # We extract a row of data
    observation = record.findAll("td")
    # Format the row as a dictionary - a "python hashmap"
    dict_observation = {
        "From": observation[0],
        "To": observation[1],
        "Pos": observation[2],
        "Ht": observation[3],
        "Wt": observation[4],
        "Birth Date": observation[5],
        "College": observation[6]
    }
    # Add the row to our DataFrame buffer
    my_data.append(dict_observation)
# Now our DataFrame buffer contains all our data.
# We can format it as a Pandas DataFrame
dataframe = pandas.DataFrame().from_dict(my_data)

# Pandas DataFrames can be turned into CSVs seamlessly. Like:
dataframe.to_csv("Basketball.csv", index=False)

# Or even MS Excel:
dataframe.to_excel("Basketball.xlsx")

Use python data structures as often as you can!

Answer 2

如果要写字节，则必须如下所示

file.write(bytes(header, encoding="UTF-8"))