SyntaxError: invalid character in identifier

What this error means

A character in your source looks like ordinary punctuation but is not the ASCII character Python expects. Modern Python names it precisely, down to the code point:

  File "demo.py", line 2
    print(“Hello”)
          ^
SyntaxError: invalid character '“' (U+201C)

The U+201C is the useful part. Python is not complaining about your logic — it is telling you that the character at that position is a typographic left double quotation mark, not the plain " (U+0022) the language grammar accepts.

Where these characters come from

• Word processors. Word, Google Docs and Pages apply 'smart quotes' automatically, turning " into “ and ”, and ' into ‘ and ’.
• PDFs and screenshots of code, re-typed by hand or copied out of a viewer.
• Chat apps. WhatsApp, Slack and iMessage all substitute smart quotes and long dashes in normal prose, and the substitution survives the paste into your editor.
• Autocorrect replacing a hyphen with an en dash (–, U+2013) or em dash (—, U+2014), or turning a straight apostrophe into a curly one inside a variable name.
• Non-breaking spaces (U+00A0) from web pages, which look exactly like a space but are not one.

The pattern is always the same: the code was written in prose software first. The cure is to paste code through a plain-text buffer, or type it directly in your editor.

The usual suspects

Each of these has an ASCII twin that Python does accept:

• “ U+201C and ” U+201D → use "
• ‘ U+2018 and ’ U+2019 → use '
• – U+2013 en dash and — U+2014 em dash → use -
• … U+2026 ellipsis → use ...
• U+00A0 non-breaking space → use a normal space
• ＝ fullwidth equals and other fullwidth forms → use =

print(“Hello”)        # ❌ SyntaxError: invalid character '“' (U+201C)
print("Hello")        # ✅

x = 5 – 2             # ❌ en dash
x = 5 - 2             # ✅

How to find the invisible ones

The dashes and quotes are visible once you know to look. Non-breaking spaces and zero-width characters are not — find them by code point:

with open("demo.py", encoding="utf-8") as f:
    for lineno, line in enumerate(f, start=1):
        for col, ch in enumerate(line, start=1):
            # printable ASCII plus the newline is all a .py file needs
            if ch != "\n" and not (" " <= ch <= "~"):
                print(f"line {lineno} col {col}: {ch!r} U+{ord(ch):04X}")

In your editor, turn on 'Render Whitespace' (VS Code: *View → Render Whitespace*) and 'Show Unicode highlight' — VS Code marks suspicious invisible characters automatically. Most editors also have a Save with Encoding / Convert to ASCII action that will refuse or flag the offending bytes.

How to debug it

1. Read the message — modern Python prints the exact character and its U+ code point. That is the whole diagnosis.
2. Fix that one character, then re-run: pasted code usually carries several, and Python reports them one at a time.
3. If the code came from a document or a chat, retype the affected line by hand rather than hunting character by character.
4. Run the scan above to list every non-ASCII character in the file at once instead of fixing them one per run.
5. Set your editor's default encoding to UTF-8 and turn off smart quotes in whatever app you copy from.

Fix it interactively

These free problems practice the string and syntax rules — repair them in the browser:

• Wrong quote type breaks the string easy
• Missing colon after function definition easy

Related messages worth knowing

• SyntaxError: the parent guide — the parse-time family this belongs to.
• unterminated string literal — a smart quote can cause this too — it opens a string Python never closes.
• UnicodeDecodeError — the encoding cousin — wrong bytes when reading data, not source.