I found a bug while checking string with find()

[DongwonTTuna]

BPO	42303
Nosy	@serhiy-storchaka, @DongwonTTuna
Files	스크린샷 2020-11-10 16.02.46.png 스크린샷 2020-11-10 16.14.28.png

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

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GitHub fields:

assignee = None
closed_at = <Date 2020-11-10.09:45:12.037>
created_at = <Date 2020-11-10.07:11:01.966>
labels = ['type-bug', 'invalid', '3.9']
title = 'I found a bug while checking string with find()'
updated_at = <Date 2020-11-10.09:45:12.030>
user = 'https://github.com/DongwonTTuna'

bugs.python.org fields:

activity = <Date 2020-11-10.09:45:12.030>
actor = 'serhiy.storchaka'
assignee = 'none'
closed = True
closed_date = <Date 2020-11-10.09:45:12.037>
closer = 'serhiy.storchaka'
components = []
creation = <Date 2020-11-10.07:11:01.966>
creator = 'DongwonTTuna'
dependencies = []
files = ['49585', '49586']
hgrepos = []
issue_num = 42303
keywords = []
message_count = 3.0
messages = ['380636', '380637', '380643']
nosy_count = 2.0
nosy_names = ['serhiy.storchaka', 'DongwonTTuna']
pr_nums = []
priority = 'normal'
resolution = 'not a bug'
stage = 'resolved'
status = 'closed'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue42303'
versions = ['Python 3.9']

[DongwonTTuna]

USED THE PYTHON-BINANCE MODULE FOR THIS
------------------------------------------------

from binance.client import Client
from binance.exceptions import *

client = Client(api_key='Your_Public_Apikey',
                api_secret='Your_Secret_Apikey')

def buy_limit_test(coin, amount):
    client.create_test_order(
        symbol=coin + 'USDT',
        side=Client.SIDE_BUY,
        type=Client.ORDER_TYPE_MARKET,
        quantity=amount)

try:
buy_limit_test(coin='HOT', amount=-19298.0)
except BinanceAPIException as E:
print(E.message.find("'quaaantity'; legal range is"))
if E.message.find("'quantity'; legal range is"):
print(E.message)
else:
print("yes")
------------------------------------------------

And the parameters.

------------------------------------------------

E.message.find("'quantity'; legal range is") = 38

E.message = "Illegal characters found in parameter 'quantity'; legal range is '^([0-9]{1,20})(\.[0-9]{1,20})?$'."

---

If I run with this

if E.message.find("'quaaaaaaaaaaaaaaaaaaaaaaaaanatity'; legal range is"):

It should be run with print("yes"), but It shows print(E.message).

But If I run with
if E.message.find("'quaaaaaaaaaaaaaaaaaaaaaaaaanatity'; legal range is") == True:

It's now run with print("yes") not the print(E.message).

I think it's a bug

[DongwonTTuna]

That was a mistake.

upload another picture file.

[serhiy-storchaka]

str.find() does not work like you think. Please read the documentation.

In your case you likely need to use the "in" operator.