Python Strings Tutorial: Slicing, f-strings and String Methods with Examples
P3.5 How to Check Text with in, startswith and endswith
Why. You often need to find rows: all emails from one company, all codes starting with "BLK", all files ending with ".csv".
What. These checks give True or False.
"a" in text— is "a" anywhere in the text?text.startswith("BLK")— does it start with BLK?text.endswith(".csv")— does it end with .csv?
How.
Check and act
- Pick the check you need.
- Make the text lower case first if case may differ.
- Use the True/False result in an if (next chapters) or a filter (pandas).
Worked example A — Is a word inside?.
Step 1 — What we do. A support ticket in Bengaluru mentions a refund.
Step 2 — Type and run this code.
ticket = "Customer wants a refund for order 778"
print("refund" in ticket)
print("cancel" in ticket)
Step 3 — Output you should see.
True
False
Step 4 — What it means. in checks the whole text. The first is True, the second False.
Worked example B — Start and end checks.
Step 1 — What we do. We check an order code and a file name.
Step 2 — Type and run this code.
code = "BLK-PUN-1001"
file = "sales_march.csv"
print(code.startswith("BLK"))
print(file.endswith(".csv"))
Step 3 — Output you should see.
True
True
Step 4 — What it means. Both are True. In pandas you will write df["code"].str.startswith("BLK") with the same meaning.
Ravindra Bagale's Tip
Make both sides lower case before checking: "refund" in text.lower(). Then "Refund" and "REFUND" also match.
Ravindra Bagale's Tip – मराठी
तपासण्याआधी दोन्ही बाजू lower case करा: "refund" in text.lower(). मग "Refund" आणि "REFUND" पण match होतात.
Ravindra Bagale's Tip – हिंदी
Check करने से पहले दोनों तरफ़ lower case करो: "refund" in text.lower(). फिर "Refund" और "REFUND" भी match होंगे.
Samajla ka? If yes, take the quiz for this chapter. If not, run every example again and change one value each time.